Why everything you thought you knew about Britain’s election is wrong

Not true. She has won every vote in the House of Commons with support from Labour MPs looking over their shoulder at their working class voters after the referendum. After the election, last June’s vote, like those in the 2015 election or the 2014 Scottish referendum, will fade into memory.

2) A clear majority will allow May to govern strongly.

Not true. Tory MPs are very disciplined right now. With an extra 50-100 entering the Commons, most from the generation that has grown up with this century’s political-media hostility to all things European, Conservative MPs will be much more difficult to handle, especially as there will not be enough ministerial posts to dangle as an inducement to good behaviour.

3) May needs her own mandate.

Not under the British system where it is quite usual for prime ministers to take over mid-term – think Gordon Brown, John Major or James Callaghan. The French Socialists won a handsome majority in 2012. It did them no good at all.

4) Labour will be crushed.

Not quite. Jeremy Corbyn is certainly not going to enter Downing Street, but there is a hunger for more radical politics – look at Bernie Sanders in America, Jean-Luc Mélenchon in France, Podemos in Spain or Syriza in Greece. Labour since 2010 is still under the shadow of the Blair-Brown-Mandelson generation and their children like the brothers Miliband and other ex-ministers. After the electoral defeat in June, Labour can rebuild.

5) The Liberal Democrats will make a come-back.

Doubtful. Some Lib Dems who lost their seats in the 2015 wipe-out are hoping to return on an anti-Brexit ticket. But single issue EU politics do not decide the composition of the House of Commons, as UKIP have discovered at every recent general election.

6) Politics will become more stable.

Hardly. There is no sense that the election will encourage the Scots or the nationalist community in Northern Ireland to make their peace with the English nationalism espoused by the hard-line on Brexit that May has taken so far. In the 65th year of her reign, the Queen will see an ever more disunited Kingdom after June 8.

7) Labour will be replaced by a more centrist party.

Dream on. This early election is extremely helpful for Labour who would have limped on miserably until 2020. Corbyn may stay on for a period, but both the election and the one or two years after allow new Labour talent to emerge to replace Corbyn and his elderly 1968 generation of leftists, and the Blair era MPs who have had their moment but are now past their listen-to date. Watch out for Sadiq Khan, by far the most interesting new politician around. By 2022, he can have proved himself as a national leader, if he gets good advice and a good team.

8) Britain with a strong Tory majority will be able to dictate terms to the EU. Ask Berlin and Paris.

With the likely arrival in the Elysée of the most pro-EU government leader in two decades, Britain will be more isolated than ever. So far, Brexit had not happened. UK firms and citizens can still trade, travel, retire and make money in Europe as a full members of the EU. When that alters, it does not matter if May has a majority of 500, she is unlikely to persuade Berlin, Paris, Madrid or Warsaw to tear up the EU rule book so that Britain can keep all the advantages of EU membership but accept none of the obligation, duties or price to be paid.

9) There will be a new Anglo-Sphere axis between Trump and May which does not need Europe.

The special relationship myth. Trump now says he wants a free trade deal with the EU not with the UK, while his invocation of Buy America trade protectionism runs counter to the Brexit promise that a new vista of free trade deal would open once the UK left Europe. Trump reveres the memory of his Scottish mother and the anger of the Scots at having their right to be European confiscated by May’s English nationalism may have percolated into the Trump worldview.

10) With her new majority May has a solid five years of political dominance in front of her.

In her dreams. Since the days of Margaret Thatcher, the Tories have been the tax-cutting party. So weak are public finances and so serious the decaying state of the NHS, schools, old-age care, prisons and the military that it is difficult to see how tax hikes can be avoided. Add in foreign investment worries over the loss of single market and customs union access and the economic horizon is very clouded. A Tory party and Tory voters faced with increased taxes and a decline in national wealth will fall out of love with May very fast, no matter the majority she wins in six weeks’ time.

Denis MacShane is a former Minister of Europe, a Labour MP for 18 years, and author of Brexit: How Britain Will Leave Europe published in January 2015