Senator Bernie Sanders will run for president proposing to enact a “Medicare for All” health care system, stave off catastrophic climate change through a “Green New Deal“ and other measures, and implement a $15 (£11.50) an hour minimum wage for all American workers, according to his aides.

Mr Sanders will also tout proposals to mandate breaking up the biggest Wall Street banks; free tuition at public colleges; lower drug prices with aggressive government intervention; new labour laws to encourage union formation; curbed corporate spending on elections; paid family and medical leave; gender pay equity; and expanded Social Security benefits for the elderly and disabled, aides said.

Mr Sanders’ criminal justice platform will include legalising marijuana, ending cash bail throughout the US, and abolishing private prisons, while he will also run on the standard Democratic policy goals of protecting young immigrants brought to the US as children and limiting the sale and distribution of guns.

Mr Sanders’ policies would require trillions of dollars in additional government spending. The senator has previously called for dramatic cuts to US military spending and a number of plans to ramp up taxes, including through heavy taxation of wealthy estates, corporations, the 1 per cent richest Americans, and off-shore tax havens. Some of his plans, like Medicare-for-All, would also require higher taxes on the middle class, though supporters say overall they would help Americans by entirely eliminating their private health care costs.

These policies are unlikely to be enacted in the form proposed by Mr Sanders even if he wins the White House, given opposition from centrist Democrats and the difficulty of moving legislation through the Senate.

Who could be running against Trump in 2020? Show all 23 1 /23 Who could be running against Trump in 2020? Who could be running against Trump in 2020? Joe Biden The former vice president - poised to be a frontrunner - has announced his run. He recently faced scrutiny for inappropriate touching of women, but was thought to deal with the criticism well AFP/Getty Who could be running against Trump in 2020? Bernie Sanders The 2016 runner-up has announced that he will be running again in 2020 Getty Who could be running against Trump in 2020? Hillary Clinton The 2016 Democratic presidential candidate and former Secretary of State says she is “still considering” whether she will run again. Getty Who could be running against Trump in 2020? Pete Buttigieg The Indiana mayor and war veteran will be running for president. If elected, he would be the first openly LGBT+ president in American history. Getty Who could be running against Trump in 2020? Kamala Harris The former California attorney general will be running for president in 2020. Introduced to the national stage during Jeff Sessions’ testimony, she has endorsed Medicare-for-all and proposed a major tax-credit for the middle class. AP Who could be running against Trump in 2020? Elizabeth Warren The Massachusetts Senator has formally launched her bid for president in 2020. A progressive Democrat, she is a major supporter of regulating Wall Street. AP Who could be running against Trump in 2020? Beto O’Rourke The former Texas congressman told Oprah Winfrey that he “has been thinking about running for presidency”, but stopped short of formally announcing his bid to run in 2020. AFP/Getty Who could be running against Trump in 2020? Wayne Messam Mayor of the city of Miramar in the Miami metropolitan area, Wayne Messam has announced his bid. He intends to run on a progressive platform against the "broken" federal government. He favours gun regulations and was a signatory to a letter from some 400 mayors condemning President Trump's withdrawal from the Paris Climate Accord. Vice News Who could be running against Trump in 2020? Kirsten Gillibrand The New York Senator formally announced her presidential bid in January, saying that “healthcare should be a right, not a privilege.” Getty Who could be running against Trump in 2020? Cory Booker The New Jersey Senator has announced that he will be running for the presidency in 2020. If he secures the nomination he said finding a female vice president would be a priority. Getty Who could be running against Trump in 2020? John Delaney The Maryland congressman was the first to launch his bid for presidency, making the announcement in 2017. AP Who could be running against Trump in 2020? Julian Castro The former San Antonio mayor announced his candidacy in January and said that his running has a “special meaning” for the Latino community in the US. Getty Who could be running against Trump in 2020? Tulsi Gabbard The Hawaii congresswoman announced her candidacy in January, but is likely to face tough questions on her past comments on LGBT+ rights and her stance on Syrian President Bashar al-Assad. Getty Who could be running against Trump in 2020? Andrew Yang The entrepreneur has announced his presidential candidacy, and has pledged that he would introduce a universal basic income of $1,000 a month to every American over the age of 18. AFP/Getty Who could be running against Trump in 2020? Marianne Williamson The author and spiritual advisor has announced her intention to run for president. She had previously run for congress as an independent in 2014 but was unsuccessful. Getty Who could be running against Trump in 2020? John Kerry The former secretary of state has said he is still thinking about whether to run. Getty Who could be running against Trump in 2020? Michael Bloomberg The entrepreneur and former New York mayor– with a net worth of around $50bn – has said he will decide by the end of February whether to seek the presidency. AFP Who could be running against Trump in 2020? Howard Schultz Former Starbucks CEO Howard Schultz has not yet ruled out running for president in 2020, despite criticism that his bid could help re-elect Mr Trump by dividing the Democrat vote. AP Who could be running against Trump in 2020? Eric Holder The former attorney general has said he will decide in “the next month or so” whether to run as a 2020 presidential candidate. AP Who could be running against Trump in 2020? Eric Swalwell The California congressman said he is “ready to do this” and will decide before April whether to run. MSNBC Who could be running against Trump in 2020? Terry McAuliffe The former Virginia governor, who worked to elect Democratic governors during 2018 midterms, said there was a “50 per cent” chance he would run. AP Who could be running against Trump in 2020? Sherrod Brown The Ohio senator is still undecided about whether to run for president in 2020. Who could be running against Trump in 2020? Mitch Landrieu The former New Orleans mayor said he doesn’t think he will run for president, but “never say never”. AP Photo/Jacquelyn Martin

The Vermont senator, who announced his bid for the Democratic presidential primary in an email to supporters on Tuesday, lost to Hillary Clinton in the 2016 Democratic presidential primary but is frequently ranked near the top of a wide-open early primary field. Republicans and centrist Democrats have said Mr Sanders promotes socialism – Mr Sanders identifies as a democratic socialist – and that his policies would bankrupt the United States at a time of already mounting fiscal deficits.

“Every 50 years, there is someone who can fundamentally alter the course of American politics. Bernie Sanders has the chance to reorient our economic policy towards workers and communities left behind instead of corporate interests,” said representative Ro Khanna (D-Calif), who has encouraged Mr Sanders to run.

Others say a Mr Sanders nomination is more likely to get President Donald Trump re-elected, with think-tanks such as Third Way arguing “ultra-progressive” candidates did less well in the 2018 midterm elections.

Here are some of the policies Mr Sanders hopes will power him to the White House.

Medicare for all

Mr Sanders plans to campaign on a promise to move America to a single-payer “Medicare for All” system, in which every American would be enrolled on a government plan. In fall of 2017, 16 Senate Democrats co-sponsored Mr Sanders’ bill, which previously garnered zero Senate co-sponsors and was criticised by Mr Clinton’s campaign in 2016 as wildly unrealistic.

“Medicare for All” would give health insurance to the approximately 30 million Americans who currently lack it, while also eliminating all premiums, co-pay, and deductibles. US health care spending per capita is more than two times larger than the average for developed nations, despite America having below-average life expectancy at birth and lagging on a number of other key health outcomes. Single-payer advocates say one government insurer would have the bargaining power to drive down costs, while giving health care for free to those who lack it.

Critics say the plan would require prohibitive, impossibly large new taxes, and question the political wisdom of forcing nearly half the country to switch from the current private plan to a public insurer. Even Democrats who have signed onto Mr Sanders’ bill have balked at its core feature of eliminating private insurance, with senator Cory Booker (D-NJ) saying he does not favour doing so.

Mr Sanders has argued that virtually eradicating private health insurance – excepting things like “cosmetic surgery, you want to get your nose fixed,” Mr Sanders has said – is essential to preventing the costs of a Medicare-for-All system from becoming prohibitive.

Conservatives have also warned that a single-payer system could also impede quality of care for those who have it, pointing to long wait times in the Canadian system.

Drastic climate action, including the “Green New Deal”

Mr Sanders has repeatedly called climate change “the single greatest threat facing our planet,” and in 2016 campaigned on cutting carbon pollution by 40 per cent by 2013, in part through an aggressive carbon tax on pollution.

Mr Sanders will sometime in the next few months also introduce a proposal to fight climate change through a “Green New Deal,” which will similarly aim to slash emissions with an enormous public works program that would create tens of millions of jobs. The effort is moving on a parallel track to that unveiled earlier this month by representative Alexandria Ocasio-Cortez, D-NY, and a number of 2016 presidential candidates in the Senate, including Mr Sanders and senators Kamala Harris, D-Calif, Cory Booker, D-NJ, and Kirsten Gillibrand, D-NY.

The upcoming Sanders plan is expected to contain significantly more details on how a Green New Deal would move America’s economy to one that zeroes out carbon emissions, according to aides to the senator, while the Ocasio-Cortez resolution supported by the other 2020 candidates mostly laid out ambitious targets for carbon reduction.

Bernie Sanders announces new legislation to tax low-paying firms 100% of cost of welfare payments to low-paid workers

The White House said in a recent statement that the Green New Deal would be a “central planning disaster” and a “roadmap to destroy the American economy,” with President Trump calling it “a high school term paper that got a low mark.” The Trump administration has not unveiled a plan to address climate change and Mr Trump has repeatedly dismissed the scientific consensus behind it. But the plan has also faced some criticism from proponents of action to address global warming, including some who have called for a greater focus on exporting renewable energy technology to developing countries and others who have argued the problem can be addressed more cost-effectively through market-based mechanisms.

In the fall, the top scientific body studying climate change found that the world had to take “unprecedented” steps to reduce carbon levels, with the globe on pace to warm by 1.5 degrees Celsius (2.7 degrees Fahrenheit) over preindustrial levels. Scientists called the report a “deafening, piercing smoke alarm going off in the kitchen.”

$15 an hour minimum wage

As he did in 2016, Mr Sanders will also campaign on a national $15 an hour minimum wage for all US workers.

America’s existing $7.25 (£5.50) an hour minimum wage has not been raised since 2009, although a number of states have passed their own increases. That includes typically conservative places like Arkansas and Missouri, suggesting the policy's potential popularity with parts of Mr Trump’s base.

Critics of higher minimum wages say they drive up business costs and reduce employment, and can also cut hours for workers, according to one study on Seattle’s $15 an hour minimum wage. Other research has contradicted those results, with left-leaning economists questioning results showing negative impacts from Seattle’s $15 an hour minimum wage

In 2016, Mr Clinton pushed a $12 (£9.20) an hour minimum wage at the federal level. The number of Democrats in Congress supporting Mr Sanders’ legislation to achieve a $15 an hour minimum wage has risen from about 60 in 2015 to more than 200 in 2018, according to Mr Sanders’ aides. Larry Kudlow, the president’s top economic adviser, has called the federal minimum wage a “terrible idea.”

Tuition-free colleges and universities; reduce student loan debt

Mr Sanders has pushed legislation to abolish tuition and fees at public four-year colleges and universities and intends to run on the plan in 2020, according to aides.

The amount of total student debt held has ballooned from $480bn (£369bn) in 2006 to $1.5 trillion (£1.15 trillion) in 2018, affecting home-ownership rates and delaying young people from starting families. A 2017 report found the price of college has increased more than 100 per cent since 2001.

Mr Sanders has also proposed cutting all student loan interest rates in half, and allowing Americans to refinance student loans at low interest rates. Researchers with the Levy Economic Institute has proposed retiring the $1.5 trillion in outstanding student loan debt, a measure not embraced by Mr Sanders.

Bernie Sanders: 'Cardi B is right' about need for Social Security to be strengthened

The Committee for a Responsible Federal Budget, a non-partisan organisation, said in 2016 that Mr Sanders’ free college plan would cost about $800bn (£515) over 10 years. Mr Sanders has proposed paying for it with a transaction tax on large Wall Street firms, which would raise $600 billion over a decade, CRFB found.

Some more centrist Democrats have stopped short of calling for that dramatic overhaul of the nation’s higher education system, with presidential candidate senator Amy Klobuchar (D-Minn) saying at a CNN town hall on Monday night, “No, I am not for free four-year college for all, no.”

Break up biggest Wall Street banks

In October 2018, Mr Sanders released an update to his plan to break up the largest Wall Street banks, barring them from holding assets worth more than $584bn (£450bn). At least six different banks -- including JPMorgan, Goldman Sachs, and Citigroup -- would be broken up by federal regulators under the proposal, which aides say is expected to play a prominent role in Mr Sanders’ campaign.

Mr Sanders touts the plan as a way to prevent a repeat of the financial crisis of a decade ago. But it has been criticised by some analysts and allies of the financial industry, who pointed to dramatic improvements in the capital cushions that banks now hold to ward against collapse. Dodd-Frank, Barack Obama‘s banking law, put new capital requirements into effect for the largest financial institutions.

Criminal justice overhaul

Mr Sanders will also be pushing a slew of measures intended to overhaul America’s criminal justice system, including to legalise marijuana, end private prisons, and dramatically reduce cash bail.

Last summer, Mr Sanders introduced legislation to end bail in federal proceedings, while giving grants to states in an attempt to get them to reduce the number of prisoners they hold on bail. In 2016, he also called for “automatic” federal investigations of deaths in police custody.

Cash bail disproportionately jails poor Americans, in particular black Americans, who cannot afford to make court-ordered payments.

Paid family leave, gender pay equity

Right now, America is alone in the developed world in not requiring businesses to give paid leave to new mothers, according to the Organisation for Economic Cooperation and Development. While mothers are not guaranteed time off by the government, families that do get time off from their employer tend to be more affluent, said Heather Boushey, executive director and chief economist at the Washington Centre for Equitable Growth.

In 2013, Ms Gillibrand released a bill to create America’s first universal paid family leave programme. It would pay workers while they take time off if they have to take care of a sick child, parent or spouse; give birth to a child; or get sick themselves. Mr Sanders is a cosponsor of the bill, and talked about the need for paid family leave in his 2016 presidential campaign.

Mr Sanders has also cosponsored legislation, titled the Paycheck Fairness Act, that would bar employers from retaliating against workers who ask about their wages, as well as making employers liable to civil litigation.