John McDonnell has abandoned his bid to become leader of the Labour Party just hours before the deadline for nominations closes.

Candidates are required to gather, by 12:30 today, nominations from 12.5 per cent of the Parliamentary Labour Party, which in the current Parliament means 33 MPs.

Mr McDonnell, who had 16 nominations, said that he was pulling out so as to give fellow left winger Diane Abbott a better chance of being successfully nominated.

Ms Abbott currently has 11 nominations, meaning that should Mr McDonnell's supporters go over to her (which is not guaranteed) she would have 27 nominations, still six short of the required number.

In a statement Mr McDonnell said, "I stood for the Labour leadership as the candidate of the Left and trade union movement so that there could be a proper debate about Labour's future in which all the wings of the party were fully represented.

"It is now clear that I am unlikely to secure enough nominations and so I am withdrawing in the hope that we can at least secure a woman on the ballot paper."

Mr McDonnell has criticised the rules that the Labour Party uses for selecting its leader, saying that they unfairly favoured big name candidates by putting the threshold so high. Ms Abbott also has condemned the rules saying that if US President Barack Obama had to face a similar procedure his campaign would have been "over before it begun".

Mr McDonnell came in for criticism yesterday after saying to a group of trade unionists that he would like to go back to the 1980's and assassinate former Conservative Prime Minister Margaret Thatcher. He later apologised and said he was only joking.

Currently only three out of the six Labour leadership contenders have acquired the number of nominations required.

Former Foreign Secretary David Miliband leads with 74 nominations, his brother and former Minister for Energy and Climate Change, Ed Miliband follows with 57 nominations, while former Minister for Children, Schools and Families, Ed Balls has exactly 33 nominations.

Andy Burnham, former Health Secretary, has 31 nominations but his campaign team claim to have secured the last two nominations that they need for him to be included on the ballot paper in the election which will go before the wider party.

The candidates who receive the required amount of nominations will then go through a series of hustings events together throughout the summer before the final ballot for the leader of the Labour Party takes place from August to September.

The winner of the election will be announced at the Labour Party conference on 25 September.