Disabled transport users are protesting over the lack of lifts at London Underground stations.
Campaign group Transport for All said occasions when lifts have been closed due to staff shortages have more than doubled since 2012.
Spokeswoman Lianna Etkind said: "Millions have been invested in making these stations accessible. Preventing disabled people from using them is not acceptable.
"Less than one in four Tube stations have step-free access and on any given day, some of these are closed due to maintenance works and breakages. When, on top of that, avoidable staff shortages shut lifts, it stops disabled and older people being able to get to work, education, and to see friends and family.
"All we want is to be able to use the Tube with the same freedom and independence as everyone else."
A demonstration will be held later outside Oakwood Tube station, which campaigners said had 13 lift closures in July and August.
Pat Hansberry, LU's operations director, said: "Industrial action made the Oakwood lift unavailable several times recently and I would like to apologise to any customers affected when the lift was out of service. I'm pleased to say the situation is now back to normal.
"Overall the lifts across our network are very reliable and were available for over 99% of scheduled hours in the last year. We have staff at every station when trains are running and try to make sure that they are always on-hand to help customers with lifts.
"Our modernisation will see 30% more visible and available staff at stations across the network, and we are working hand-in-hand with disability groups to make sure we have the knowledge and confidence to offer them a great service."