Will a big defeat for the Tories in this week’s local elections force Theresa May to rethink on Brexit?

The Conservatives are braced for a bloody nose in this week’s local government elections.

Most of the 8,400 seats on 248 councils up for grabs were last fought on the day David Cameron won an overall majority at the 2015 general election. So the Tories have more ground to lose.

Certainly the contest comes at a bad time for the Tories; their support among those who voted Leave in the 2016 referendum has slumped since the UK failed to depart the EU on schedule in March.

Indeed, one survey suggested that 40 per cent of Tory councillors plan to vote for Nigel Farage’s new Brexit Party in the European parliament elections due on 23 May.

The Tories have tried to limit the damage by arguing the council elections should be about “bins not Brexit”.

But even if disenchanted Tory supporters stay at home rather than switch parties, the Liberal Democrats and Labour will benefit.

Robert Hayward, the Conservative peer and elections expert, is predicting the Tories will lose more than 800 of the 4,600 council seats they are defending on Thursday.

Theresa May’s Eurosceptic critics, who claim she is deeply unpopular on the doorstep after failing to deliver Brexit, would seize on such losses as evidence that she should stand down immediately. They may revive plans to change Tory rules so they can force another vote of confidence in her as party leader in June, rather than wait for a year (until December) as the current rulebook states.

However, Ms May is likely to hang on and could make one final attempt to win a Commons majority for her Brexit deal before the European elections by introducing the withdrawal agreement bill. The move might be announced to deflect attention from poor council election results.

Measuring the “Brexit effect” on Thursday will not be easy, as Change UK (formerly the Independent Group) and Mr Farage’s party are not contesting the local elections and Ukip is standing in only 16 per cent of seats, down from more than 40 per cent in 2015.

Although Ms May will be pained by the loss of Tory councillors, she will be more worried about the prospect of a crushing defeat in a humiliating “Brexit election” that follows three weeks later when (almost certainly) we go to the polls to choose a new raft of MEPs.