Parliament is currently stuck in limbo. Boris Johnson's government is too weak to pass crucial legislation but his opponents have twice rejected his plea to end the impasse by backing a snap election.

By blocking an October election, Labour, the Liberal Democrats and the SNP believe that the Prime Minister now has no choice but to ask for an extension to Article 50 beyond the current 31 October deadline.

With Mr Johnson having secured his premiership on a "do or die" approach to leaving on this date, any further extension would be very damaging to his credibility and his electoral chances.

In fact, a delay of a few weeks in holding an election could be the difference between a thumping Tory majority and a hung parliament.

The reason for this lies in the volatility of the polls. So far this year three parties - the Brexit Party, Labour and the Conservatives - have led in the Telegraph's rolling polling average at some point, while back in June it looked as though we'd entered an era of four-party politics.

Since Mr Johnson's election as Tory leader, the Conservatives have managed to chip away at the Brexit Party's support, while Labour has been less successful at winning support away from the Lib Dems.