Mr Sunak’s camp pointed to figures showing a large 12.5 per cent swing to their candidate when compared to Ms Mordaud over the past six days. However, while Mr Sunak made big gains over Ms Mordaunt, the poll showed Mr Sunak made a slight improvement over Ms Truss. His own rating was unchanged at 35 percent, up 2.5 percent from July 12. A Sunak campaign source said Mr Sunak’s swing away from Ms Mordaunt was a “pretty big swing in that period of time”. The hope now for the Sunak camp is that more Tories will rally to Mr Sunak’s cause the more they see of him as the chases begin. The party has pledged to hold up to 12 constituencies across the country next month. But there was further concern among MPs backing Mr Sunak after Conservative campaign headquarters confirmed they would send out postal ballots on August 1, before most of the inductions took place. The postal ballots, which also contain a QR code to allow members to vote online if they wish, will land on the doorsteps of party members between August 1 and 5. Voting closes at 5pm on Friday 2 September, with the winner announced on Monday 5 September, according to internal party documents seen by The Telegraph. A Tory MP from Red Wall, who supports Mr Sunak, said: “It is certainly fair for all members and both candidates to have the opportunity to see the candidates at their own regional rallies before receiving the ballots. “We are choosing a new prime minister, not a new leader. It’s not like we can send it back if it turns out not to fit.”