Today Boris Johnson will try for a third time to persuade MPs to vote for an early election. Labour, however, seems unlikely to support his proposal, just as it failed to do on the two previous occasions.

How well calibrated are the two parties’ positions? Is Mr Johnson taking a risk in calling for a contest? Might Labour come to regret a decision to oppose a ballot?

After all, it is not immediately obvious why Conservative voters should necessarily back the idea or Labour supporters oppose it. Conservatives might simply regard an election as an unwelcome delay to Brexit, while Labour voters might be inclined to regard an early poll as a chance to end Tory rule.

At the end of last month Opinium asked