One punter could earn themselves hundreds of thousands of pounds if Boris Johnson ends up as Prime Minister.
A Ladbrokes customer staked £2,000 on the former London mayor being made PM by July 1 – at odds of 100/1.
The gambler, from Chelsea, west London, placed the bet on Wednesday, and could take home £200,000 if Mr Johnson is elevated to Number 10.
Foreign Secretary Mr Johnson is re-standing as Conservative candidate for Uxbridge and South Ruislip at the upcoming election on June 8.
The 52-year-old was widely expected to run for the Tory leadership last year following the resignation of David Cameron in the wake of the EU referendum.
His plans were scuppered, however, when Michael Gove announced he would also launch a bid for the top spot.
Theresa May called the snap election last month, with voters due to go to the polls next Thursday.
A failure to build a larger Tory majority in the House of Commons than the one achieved by Mr Cameron at the 2015 election would arguably be seen as a moral defeat for Mrs May and the party.
She hopes to secure her own mandate as Prime Minister and “strengthen her hand” ahead of Brexit negotiations.
But recent polls have suggested wildly varying projections about what the Conservatives should expect on voting day.
And Mrs May has come in for repeated criticism for refusing to appear on any live television debates with Labour leader Jeremy Corbyn.