In a letter sent to Tory members seen by Sky News, the leader of Conservative Party members confirmed that postal ballots would arrive “a little later than we originally said” as “we’ve taken some time to add some extra security” in the process. Members were previously due to receive their postal votes this week. However, the email sent to members says they should receive their ballot by Thursday 11 August. Politics Hub: Sunak allies attack Truss public sector pay plan The letter adds that voting more than once in the ongoing leadership contest will be treated as an “offence” and warns that any member found to have voted more than once will have “their party membership withdrawn”. It adds that Tory members can either vote by post or online. But the Conservative Party confirmed that security fears had forced it to abandon plans to allow members to change their vote for the next leader later in the contest. Allies of leadership hopeful Liz Truss are believed to have worried that the original rule allowing Tory members to change their vote in the contest would work in favor of her rival Rishi Sunak. The rules of the leadership contest, set by the 1922 Committee of MPs and the Conservative Party board, state members must vote only once, but if a “double” vote is recorded, the second will be counted. CCHQ described it as a minor delay and was unable to provide further guidance. A Tory Party spokesman said: “We have consulted with the NCSC throughout this process and have decided to increase security around the ballot box process. Eligible members will start receiving ballot packs this week.” Earlier on Tuesday, a new poll showed Ms Truss had widened her lead over Mr Sunak in the leadership race. It comes as Mr Sunak struggles to gain ground during a key week in the contest for the keys to Number 10. The latest YouGov poll of Tory members for The Times newspaper shows Ms Truss’ lead has grown to 34 points in the Tory leadership race, with 60% of party members now saying they will vote for the minister of Foreign Affairs to succeed Boris Johnson as Prime Minister. This compares with just 26% for former chancellor Mr Sunak. The poll, conducted over the past five days, shows Ms Truss is now ahead of Mr Sunak across all age groups, in different parts of the country and with both men and women. The only category where she beats Mrs Truss is among Tory Remain supporters. The YouGov survey published on Tuesday also found that almost nine out of 10 Tory members have now decided how they will vote ahead of ballots going out this week. But it will concern both potential leaders that more than 50% of party members believed that whoever was elected to succeed Mr Johnson would lose the party’s majority at the next election. Just 19% of members believed Mr Sunak could lead the Tories to victory, while 39% believed Ms Truss could fend off a challenge from Labour. Voting will end on September 2nd and the winner is expected to be announced on September 5th. As the leadership race continues to heat up, Mr Sunak and Ms Truss will be back in front of the cameras this week on Sky News. The Battle for Number 10, which will take place on Thursday, August 4 at 8 p.m. to vote in favour. This will be followed by an in-depth interview with Kay Burley. The program will be broadcast live for 90 minutes and free-to-air on Sky News channel 501, Freeview 233, Sky Showcase channel 106 and Sky News digital channels.