Backbencher Andrew Mackinlay's office said that he would formally nominate the Chancellor giving him the 308 nominations needed to go through unopposed.

It would leave left-winger John McDonnell unable to secure the 45 nominations - including his own - to get his name on the ballot paper.

Mr McDonnell earlier refused to concede defeat. However, he later conceded defeat, saying that it was "mathematically impossible" for him to gain the 45 nominations needed to go forward as a candidate.

By 6pm on Wednesday Mr Brown had the nominations of the 307 of the 353 Labour MPs eligible to vote in the leadership election.

With deputy speaker Sylvia Heal having said that she will not nominate either contender, that left Mr Brown needing the backing of just one more MP.

Mr Brown's camp said that they would await the formal voting figures announced by the party before making any statement.

While the Chancellor saw his tally of nominations rise steadily throughout the day, Mr McDonnell is stalled on 29.

Earlier he issued a last ditch appeal to Labour MPs to ignore his left-wing politics and nominate him simply to ensure ordinary party members were not denied the chance to elect the party's leader.

However, with Mr Mackinlay's announcement his hopes of achieving that appeared to have vanished.