The British Parliament has formally been opened with the "most radical Queen's Speech in a generation" laying out Prime Minister Boris Johnson's plans to use his commanding majority to take the UK out of the European Union and shake up the country's public services.

Johnson's Conservative Party won an 80-strong majority in the 650-seat House of Commons last week on a pledge to "get Brexit done" by leaving the European Union on January 31, and a broad promise to end years of public spending austerity.

Now Johnson has to turn his election pledges into political reality.

Queen Elizabeth and Prince Charles at the 66th State Opening of Parliament. (AAP)

The Queen's Speech — written by the government but read out by the monarch from atop a golden throne in the House of Lords — rattled through several dozen bills that the government plans to pass in the coming year.

Addressing both Houses of Parliament, the Queen said her government's "priority" was to take the UK out of the EU on January 31 - but that it would also embark on an "ambitious program of domestic reform that delivers on the people's priorities".

She said the "integrity and prosperity" of the UK is of the "utmost importance to my government" - amid fresh calls from the SNP to grant Holyrood the power to hold a second vote on Scottish independence.

The first priority will be Johnson's Withdrawal Agreement Bill, the law needed to make Brexit a reality.

Queen Elizabeth II formally opened the UK Parliament with the mandate of securing Brexit under Boris Johnson's lead. (AAP)

It must become law before January 31 if Johnson is to stick to his timetable, and the government plans to hold the first significant vote on it Friday.

The bill commits Britain to leaving the EU on that date and to concluding trade talks with the bloc by the end of 2020.

Johnson insists he won't agree to any more delays — a vow that has set off alarm bells among businesses, who fear that means the country will face a "no-deal" Brexit at the start of 2021.

Trade experts and EU officials say striking a free trade deal within 11 months will be a struggle.

Her majesty's address has been described as the "most radical Queen's Speech in a generation". (Royal Family)

European Commission President Ursula von der Leyen yesterday called the timetable "extremely challenging."

The government also plans to pass several other Brexit-related measures, including a new immigration system that will be introduced after Brexit, when EU citizens will lose the automatic right to live and work in the UK, and new structures for agriculture and fishing.

Johnson also promised "an ambitious program of domestic reform," including a law committing the government to spend more on the National Health Service, which has struggled to keep up with growing demand during a decade-long funding squeeze by previous Conservative governments.

There were tough-sounding announcements on law and order, including longer sentences for people convicted of terrorist offenses and other serious crimes.

Several of the measures are likely to prove contentious.

The government plans to set up a "Constitution, Democracy and Rights Commission" that could lead to reform of the Supreme Court.

The court angered the government by ruling in September that Johnson's decision to suspend Parliament was illegal.

The government also intends to pass a law protecting military veterans from "vexatious" prosecutions. The question of whether veterans who served decades ago in Northern Ireland should be open to war crimes prosecution is hugely controversial.

Johnson also promised to lessen regional inequality and bring greater unity to the United Kingdom, which is made up of England, Scotland, Wales and Northern Ireland. But Brexit is making that more difficult.

The Queen's State Opening address brings together all three of the UK's parts of Parliament, including members of the House of Commons, the House of Lords and the Monarch. (Royal Family)

Scotland voted to remain in the EU in Britain's 2016 referendum, and last week most Scottish seats in Parliament were won by the Scottish National Party, which opposes Brexit and wants Scotland to become independent of the UK.

SNP leader Nicola Sturgeon says that means Scotland should be able to hold a vote on independence, an option Scots rejected in a 2014 referendum that was billed as a "once in a generation" event.

Sturgeon said today she had formally written to the Prime Minister requesting the power to hold a new independence vote.

"The alternative is a future that we have rejected being imposed upon us," Sturgeon said in Edinburgh.

The tension between Prime Minister Boris Johnson and Labour leader Jeremy Corbyn was visible during the Queen's Speech. (AAP)

"Scotland made it very clear last week it does not want a Tory government led by Boris Johnson taking us out of the European Union."

Johnson has said he will refuse, and the two sides look set for a slow-burning constitutional showdown.

The Queen's Speech was the centerpiece of the State Opening of Parliament, a blend of politics and pageantry that usually takes place about once a year.

Britain saw its last state opening just two months ago, soon after Johnson took over as prime minister from Theresa May through a Conservative Party leadership contest and shortly before the early election that returned him to power.

The pomp was toned down for the queen's second visit this year.

There were still officials with titles like Black Rod, scarlet-clad yeomen of the guard and lords in ermine-trimmed robes. But the 93-year-old monarch was driven from Buckingham Palace to Parliament in a car, rather than a horse-drawn carriage, and wore a pale blue dress and matching hat rather than robes and a diamond-studded crown.

Johnson will make his mark on the government more decisively in the new year. He's expected to shake up his Cabinet and merge or even eliminate some ministries — all under the guiding eye of chief adviser Dominic Cummings, a self-styled political disruptor.