Sarah Olney has proposed taller ticket gates at the 20 London stations with the highest fare-evasion rates, alongside an independent audit of how Transport for London measures unpaid journeys, as she seeks the Liberal Democrat nomination for the 2028 mayoral election.

The Richmond Park MP wants to draw on the Department for Transport’s £33m gate line programme, announced in the summer, to pilot more secure barriers. Fare evasion costs TfL between £190m and £210m annually, making lost revenue the central financial argument for her proposal.

Olney accused Labour mayor Lord Sadiq Khan of being “asleep at the wheel on fare dodging”. She said: “Leaving gates open and unstaffed is a kick in the teeth for the vast majority of Londoners who are forced to pay the bill for those cheating the system.”

Her six-point plan includes an independent review intended to establish the scale of evasion and scrutinise the network’s estimates. She also claimed the problem was particularly severe on tram services across Croydon, Sutton and Wimbledon.

TfL says it is working towards an evasion rate of no more than 1.5%. There is already some overlap between Olney’s proposed approach and work outlined by the mayor: in July, Khan confirmed that TfL would monitor new-style barriers at High Wycombe to assess their effectiveness in deterring evasion and protecting revenue.

The distinction is between testing a barrier’s effectiveness and committing to a wider London pilot. Olney’s proposal identifies where she wants taller gates trialled, but their effect on fare evasion remains to be established. Her audit would separately examine whether the existing estimates capture the problem accurately.

Olney announced her intention to seek the nomination in September. Her rival, Robie Blackie, who stood for the party in 2024, announced his bid last month. He has called for a bold campaign focused on improving London’s police and making housing cheaper.

The Liberal Democrats finished third in 2024 with 5.8% of the vote, just 70 votes ahead of the Greens. Khan won with 43.8%, while Conservative candidate Susan Hall took just under a third. Khan has yet to say whether he will seek a fourth term.

For Olney, the immediate contest is therefore within her own party; the practical test of her transport pledge would be whether more secure gates recover enough unpaid fares to justify their use.