Ken Livingstone announced he would be campaigning to be Labour’s 2012 mayoral candidate, from Croydon today.

The first elected London Mayor, who served between 2000 and 2008 before he was ousted by Boris Johnson, said he would campaign on keeping down public transport fares.

He said under Boris Johnson, transport fares had risen by a third.

If elected, he also pledged to ditch “wasteful” schemes such as the new Routemaster bus and the floating airport in the Thames Estuary.

Mr Livingstone said his overriding reason for wanting to be elected Mayor was to protect Londoners from the recession and “the effects of the government’s policies”.

Mr Livingstone will be campaigning against Oona King, the only other Labour candidate to throw her hat in the ring.

Labour hopefuls have until June 18 to put their names forward.

The winner will be announced on September 22.