The Liberal Democrats have launched their 2019 election manifesto, with the slogan Stop Brexit Build A Brighter Future. It sets out the polices the party aims to introduce should it win the election.

The full document runs to 96 pages and contains pledges on a variety of subjects, with Brexit and the NHS to the fore. But what are the promises that will grab the public's attention, and, potentially win over voters on polling day, 12 December?

1. Stop Brexit

Article 50 would be revoked and Brexit cancelled.

The words "STOP BREXIT" appear in large capital letters on the front of the manifesto. Uniquely among UK-wide parties, the Liberal Democrats are promising to revoke Article 50 immediately - and stop Britain leaving the EU without another referendum.

The pledge stands out from Labour, who would offer another vote, and the Conservatives, who are promising to leave the EU in January. The Liberal Democrats believe the clarity of this approach won them votes during the European elections - and can be a vote-winner again. It also underpins their plans to increase public spending - the Liberal Democrats say staying in the EU would deliver a £50bn "Remain bonus" to the economy - money that could be spent on public services.

This policy would apply to the whole of the UK.

Media playback is unsupported on your device Media caption Lib Dem leader Jo Swinson is pressed on whether she'd block a Tory or Labour government

2. A penny income tax rise for the NHS

Raise £7bn a year over five years - a total of £35bn - to spend on the NHS and social care.

The one penny in the pound extra on income tax will be ring-fenced for the NHS and social care. But this is a vague concept and simply means the party has promised £7bn a year more for health and social care and identified how the revenue might be raised. It will be hard to track precisely how the money is spent.

Longer term, the party wants to move to a dedicated health and care tax. which is called "hypothecation", to reassure voters their money is for key public services. The big problem is that in an economic downturn the tax receipts might fall, and, if so, would the government feel obliged to cut health and care spending? If the Treasury was obliged to top up funding from the central pot, the benefits of hypothecation would be lost.

Scotland, Wales and Northern Ireland all run their own health services, but they will also benefit from any extra funding.

3. Free childcare

All children aged two to four will qualify for 35 hours a week, 48 weeks a year.

This is an eye-catching and potentially eye-wateringly expensive election promise. According to the independent economists at the Institute of Fiscal Studies, it would represent an extra £13bn a year, which is four-and-a-half times higher than the current level of spending.

This is an expensive offer that could attract criticism as a big giveaway to some better-off parents, while not helping the poorest children who might benefit most. Currently all three to four-year-olds with both parents working can access 30 hours free childcare, unless either parent earns more than £100,000 a year.

Childcare is a devolved issue.

4. Generate 80% of electricity from renewables

Achieve this target by 2030 to reduce carbon emissions.

Even by the standards of an election busy this target is ambitious. We are already on a path of rapid decarbonisation - with 40% of our electricity produced by wind, solar and biomass in the third quarter of this year.

And recent government projections suggest that contribution is set to rise to just under 50% over the next decade. So the Liberal Democrats' plan for 80% would mean the extremely rapid construction of many more solar farms and wind turbines on land and out at sea. Only the Green Party envisages a faster transition.

These targets would apply to the whole of the UK.

5. Tax frequent flyers

Those who take the most international flights face a tax rise, while costs would come down for people who take one or two international return flights a year.

The statistics suggest a frequent flyer levy is justified. More than half of those surveyed by the Department for Transport in 2014 said they had not taken any flights in the previous 12 months. The Lib Dems' policy becomes less radical when you consider people only taking one or two return flights a year would pay less tax. The UK already has one of the highest rates of Airport Passenger Duty in the world.

Unsurprisingly airline bosses are against a rise. Ultimately they could pass any additional cost on to passengers. Then it comes down to whether their customers are prepared to pay more. With aviation's impact on the climate in sharp focus, some type of tax reform feels inevitable.

This policy would apply to England, Wales and Northern Ireland. Air taxes are devolved to Scotland.

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6. Recruit 20,000 more teachers

Spend £10.6bn more a year on schools and hire thousand of new teachers by the end of the next Parliament.

The promise of another 20,000 teachers in England's schools and falling class sizes may be deceptively hard to deliver. Schools in England decide how to spend their own budgets. Many of the posts that have disappeared have been support staff such as counsellors or librarians.

Head teachers may restore these posts first. There is so much pressure to get results that teachers' jobs are often the last to go, although some are quietly not replaced. There are 453,400 teachers already in England but there is also a population bulge hitting secondary schools, which is due to continue until 2025. So while primary class sizes might shrink, secondary classes could grow.

Education is fully devolved to each part of the UK.

7. Legalise cannabis

Help to break the grip of the criminal gangs by introducing a legal, regulated market for cannabis.

Legalising the recreational use of cannabis for adults is one of the most radical of the Lib Dems' proposals, having first appeared in its 2017 manifesto. The Lib Dems believe it would help "break the grip" of the criminal gangs that profit from the lucrative trade in illegal drugs. And it's a powerful argument.

But evidence suggests legalisation would not end the cannabis black market for under-18s, nor for those wanting more potent strains. There is also concern it could encourage greater use of the drug and act as a gateway to more harmful substances - which is why most of the other political parties will not make the same, bold commitment.

This policy would apply to the whole of the UK.

8. Freeze train fares

The freeze would apply to all peak-time and season tickets for the next Parliament.

Too many commuters in too many parts of Britain have suffered an unreliable service for too long. So a fare freeze for all peak-time and season tickets seems…fair!

The Liberal Democrats say the taxpayer would foot the bill. They reckon it will cost £1.6bn over five years. For context, operating and maintaining the UK's rail infrastructure costs about £6bn a year. When you consider inflation, the policy in effect makes rail travel cheaper.

The more intractable issue is how to make it better. The Liberal Democrats are committed to completing the HS2 high-speed railway, which would create extra capacity. They say they would also spend £15bn on enhancements to the existing rail infrastructure over five years. That's above recent rates of spending.

Rail fare regulations are devolved.

9. Give zero-hours workers a 20% rise

Pay boost the higher minimum wage for people working on zero-hours contracts.

Some form of pay bonus for insecure work has been suggested before. Matthew Taylor, who led a review into UK working practices, has suggested a 15% minimum wage boost, echoing a similar policy in Australia, whereby a 25% pay premium is added to casual work.

Jonathan Cribb, senior research economist at the Institute for Fiscal Studies, says the proposal is interesting for two reasons: It could reduce the number of firms who want to hire people on zero-hours contracts and it could mean people in regular employment might seek out a zero-hours contract because they like the flexibility. He says: "So essentially, there could be fewer opportunities for these contracts and more people searching for them."

This policy would apply to most workers across the UK.

10. Resettle 10,000 refugees a year

In the next 10 years, 10,000 more unaccompanied refugee children will also be allowed into the UK.

Since 2015, about 16,000 refugees have found sanctuary under the Vulnerable Person Resettlement Scheme, which was set up for those affected by the conflict in Syria. In June, the government announced that in 2020 it would replace the programme with a global resettlement project for 5,000 refugees each year.

The Lib Dems' proposal, therefore, would double the number taken in by the UK, with an extra 1,000 unaccompanied children allowed to settle each year. The practical difficulties associated with the idea include finding enough local authorities prepared to house the refugees and ensuring that they're not exploited once they're in the UK.

This policy would apply to the whole of the UK.

11. Tough borrowing rules and targeted tax rises

Brexit bonus funds new teachers, flying taxes fight climate change.

The Liberal Democrats are positioning themselves as the most fiscally virtuous of the major parties, with the toughest rule on borrowing. That means they've raised taxes, and are going to be the only party promising a basic rate tax rise.

Many of the tax rises are specifically earmarked for spending commitments. Known as hypothecation, this is very much out of fashion at the Treasury which prefers everything to go into a central pot. The manifesto says the air passenger duty rise will go to the fight against climate change, business taxes will pay for an increase in free childcare and an extension of free school meals. The problem is that if any of these sources of funding falls short individually, will they really defund the spending promises associated with it?

12. Build 300,000 new homes a year

Bring the supply of new houses into line with demand.

A total of 300,000 new homes a year is the current official target for England, but governments have consistently struggled to meet it - England gained only 220,000 last year. This is due in part, to the whims of builders and planning factors.

More striking are tweaks to the tax system. These include permission for local authorities to levy up to six times the typical council tax fee on homes left empty for more than six months a year, and basing stamp duty on a property's energy rating. For tenants, there are plans to help with up-front deposit costs through a Help to Rent loan for all first-time renters under 30.

Housing is devolved so this policy would apply to England only.

To find out more read our simple guide to the Liberal Democrats

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