British prime minister Theresa May unexpectedly called for an early election on Tuesday, which she is almost certain to win.

• Opinion polls have consistently put May’s Conservative Party up to 20 points ahead of Jeremy Corbyn’s Labour.
• Under Britain’s first-past-the-post system, the pro-European Liberal Democrats and the nationalist United Kingdom Independence Party, who share third place in the polls, stand little chance of gaining many seats.
• The Scottish National Party sees the early election as an opportunity to assert its dominance north of the border. Majority Scottish support for the nationalists could strengthen their argument for a second independence referendum.

Unity

After coming to power in the wake of the Brexit referendum, May rejected calls for snap elections, arguing that she had a sufficient mandate.

She justified her change of heart on Tuesday saying there is too much disunity in British politics:

Division in Westminster will risk our ability to make a success of Brexit and it will cause damaging uncertainty and instability to the country.

Labour and the Liberal Democrats have been critical of her negotiations with the EU. The SNP have said they may even vote against an exit deal.

But then, that is their role as opposition parties.

If anything, Labour’s indecisiveness on Brexit is disappointing the 48 percent of Britons who voted against leaving the EU in 2016.

Timing

Andrew Sparrow argues in The Guardian that holding an election this year as opposed to waiting for 2020 could make Brexit easier for May.

She is almost certainly going to have to make concessions that will be unpalatable to hardliners. For example, the remaining 27 member states are not even willing to discuss a post-Brexit trade deal unless the United Kingdom agrees to pay its share of the EU budget and pension liabilities, the so-called exit bill. Brexit fundamentalists consider this a form of blackmail.

If the election were in 2020, May would have to explain to voters what Britain was still paying the EU for despite being on the verge of leaving. “If she could win a majority now, she would be safe for another five years.”

Conviction

Others argue May seeks freedom from the Tory right, which currently has the power to hold the government hostage.

The Conservatives only have a working majority of seventeen.

But Janan Ganesh argues against this line of thinking. In a timely column, published before the prime minister made her announcement, he writes that cynics underestimate May’s conviction:

If she had a lavish majority in Parliament and no reason to heed her MPs, she would govern in much the same way.

To May, the choice for Brexit was a vindication of her domestic policies and her style of leadership:

She favors a gentle society over a dynamic one, views the market with the suspicion of a mild social democrat and takes nationhood more seriously than the universalist end of Christianity tends to.

It is for this vision, which is more conservative than the party campaigned for in 2015, that May seeks the country’s support.