Livingstone, who had already won the support of Unite, has also been endorsed by ASLEF and UCATT.
The latest endorsements mean Livingstone now has support of two thirds of the nine trade union organisations affiliated to the London Labour Party which has led some supporters to suggest the momentum is with their candidate.
The former Mayor faces competition for Labour’s nomination from former MP Oona King who earlier this week announced a raft of big name financial backers including historian Simon Schama and pollster Peter Kellner.
Under Labour’s selection process the unions comprise 50 per centre of the electoral college that chooses the Mayoral candidate with party members forming the other half.
Confirming his union’s support for the former Mayor, TSSA General Secretary Gerry Doherty said: “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. We think he will be the right man to lead London into the Olympics and beyond.”
In a statement issued on Thursday, Livingstone said the growing levels of union support for his bid showed “the London Labour movement wants and expects a Mayoral candidate who will stand up for London, opposing the cuts and privatisation threatened by the government and Boris Johnson and who knows how to use every lever to work to get the best for Londoners.”
“Trade union recommendations to their members give a clear indication of the unity, weight and breadth we are pulling together. Trade unions represent Londoners in thousands of workplaces and they know directly what the combination of economic difficulty, fare increases and cuts will mean for people.”
Livingstone’s campaign was further boosted on Friday afternoon when Eltham MP Clive Efford endorsed him, just a day after Livingstone and King took part in a hustings for party members in the area.
Efford said during his term at City Hall Livingstone had “delivered real improvements for my constituents in Eltham from extending bus services to putting in dedicated safer neighbourhood police teams.”
The MP added: “We need a Mayor who will stand up for us, who is London through and through and will always put London first. That’s why I’m backing Ken to be Labour’s candidate for Mayor.”
