Diane Abbott's campaign to become leader of the Labour Party received a minor boost after she received the support of two of the 14 trade unions affiliated to the Party, however Ed Miliband also received a strong boost from one of Britain's biggest unions.

ASLEF, a union for train drivers has backed Ms Abbott, following a declaration of support from the Transport Salaried Staff's Association (TSSA) given last week.

Keith Norman, General Secretary of ASLEF, said, "ASLEF supports Diane for leader as the candidate committed to a publicly run, publicly owned railway. We'll be advising all members to give her their first preference vote in the leadership contest."

Gerry Doherty, General Secretary TSSA, also said, "Diane was the only candidate who supported our policy of a publicly owned railway without any quaification or hesitation.

"Labour went into the 1997 election saying it was going to reverse the Tories privatised railway but never did anything to undo that damage over the past 13 years.

"We want an affordable state owned railway system like the rest of Europe. Diane agrees with that very sensible policy and we shall be asking our members to vote for her accordingly."

TSSA has also come out in support of Ken Livingstone, who is currently seeking re-selection as Labour's candidate for London Mayor ahead of the 2012 mayoral election. He is currently battling for the nomination with the former MP for Bethnal Green and Bow, Oona King.

Mr Doherty said of Mr Livingstone, "Ken did a very good job for transport during his eight years at City Hall. He had the courage to introduce the congestion charge and he invested heavily in the tube and bus systems.

"He has also been proved absolutely correct in opposing the PPP being imposed on London by the previous government in the shape of Metronet and Tube Lines, both now thankfully back in the public sector."

Ed Miliband, one of the frontrunners in the Labour leadership contest, has perhaps received one of the most sought after union nominations after the general GMB union threw its support behind him yesterday.

His brother David Miliband has already secured the support of the USDAW and Community unions.