London Mayor Boris Johnson has pledged to lower the age of free public transport to 60 if he is re-elected in May.

The Conservative politician wants to extend access to the capital’s Freedom Pass, which gives older and disabled London residents free bus, tube, DLR and London Overground travel.

Under current changes, the age at which residents become eligible for the pass is being raised to 66.

The announcement comes on the day of the first public debate between Mr Johnson and Ken Livingstone at a hustings event organised by Age UK in front of 200 pensioners.

As the two mayoral candidates battle it out for what has been dubbed “the grey vote”, Labour representative Mr Livingstone also pledged to cut Londoner’s energy bills by £150-a-year.

The election takes place on May 3.

Mr Johnson said: “I said that Londoners over 60 would get the 24-hour Freedom Pass and I’m a man who keeps my promises. Hard-working people who have done the right thing and paid their taxes in expectation of free travel on retirement are right to be annoyed at those who seek to take that away.

“I’m conscious that my promise of free travel has been eroded by a decision from Ken Livingstone’s Labour party to raise the age where Londoners qualify for the Freedom Pass.”