Writing in the Telegraph, the Mayor suggested employers should be be able to buy season tickets on behalf of staff and then deduct the cost from employees’ pre-tax earnings.
Mr Johnson says this could save workers £251 per year.
Since coming to office in 2008 the Mayor has introduced above-inflation increases to Transport for London fares each year.
During last year’s Mayoral election he denied claims that TfL had a cash surplus which could be used to fund a fares freeze or cut. But in recent months his Conservative colleagues on the London Assembly have urged him to look at ways of halting the annual increase.
Val Shawcross, Labour’s Transport spokeswoman on the Assembly, said the Mayor’s comments proved fares were too high but that his suggested remedy would fail to help “those people who do not have set hours”.
She added: “Boris needs to do something that helps all Londoners who are struggling with the cost of living crisis, he will shortly be announcing next year’s fare rise.
“Rather than another year of raising fares above inflation he needs to keep his promise and ‘bear down on the fares’, Londoners cannot afford yet more inflation busting fare rises.”
Labour peer Andrew Adonis, a former transport secretary and potential candidate for 2016’s Mayoral elections, has also dismissed the Mayor’s proposal.
Writing for the New Statesman, Lord Adonis said: “This is another gimmick, not a sensible policy. Why is Boris punting it out at all? As a smoke-and-mirrors distraction from the real issue, which is whether this January fares will, yet again, rise faster than inflation.
“His tax wheeze enables him to say he favours a better deal for working Londoners but is being stopped by the dastardly Treasury. And even if it happened, it would cost less than a fares freeze, and – dare one say – be more targeted on potential Tory voters.”
On Wednesday Green Party Assembly Member Jenny Jones will challenge the Mayor about the link between this year’s fares increase and the purchase of 600 New Bus for London vehicles.
Baroness Jones said: “This is the first year when the Mayor’s vanity bus will really start contributing to fare rises in London. Londoners are paying higher fares, but getting no expansion of the bus service.
“Instead, fares money is now being used to employ a lot of health and safety officers on the backs of these new buses.”
She will question the Mayor about the link at Wednesday’s meeting of the entire Assembly.
