A 'Tube-in' is being planned online to oppose union strikes and a rumoured delay to the start of Night Tube services 12 September.

"Let's do a sit-in on the last Tube on the night of 12 September," wrote the user alikaz on the popular web forum Reddit on 12 August. The idea took off and came in response to a report by the BBC that said the start of all-night service on weekends may be delayed. The service will be offered on the Victoria, Jubilee, and parts of the Central, Piccadilly, and Northern lines.

If any delay due to strike action pushes back the launch of the Night Tube, Redditors said they plan to push back against it. It would be "sort of like a citizens strike, so the Tube workers can't go home?" said Reddit user Lolworth as the group hammered out the details online.

The new 24-hour service is due to start on 12 September. A spokesperson for Transport for London (TfL) said the rumours of a delay are probably coming from the drivers' trade unions. "We are working towards the launch date to reach an agreement," said the spokesperson.

Three unions have 24-hour walkouts planned for the 25 and 27 of August. These plans follow strike actions on 8 July and 5 August disputing the Night Tube and other grievances. Workers are demanding a better "work-life balance" and oppose TfL's "insistence that staff are contracted to work 24/7," Unite union regional officer Hugh Roberts told IBTimes earlier this week.

Negotiations about the issue have dragged on for six months. TfL argues that the new service will create 500 more jobs and is in demand from Londoners. Arguments have also been made for automating the Underground.

Some Redditors proposed taking over Tube carriages, staging a sit-in at several Tube stations throughout the capital, or staging protests outside stations. Other suggestions included setting up a makeshift cinema with a projector in Leicester Square station and creating a picnic-like atmosphere with music in Green Park.

"We are against the fact that this has not already been sorted," reads the mission statement of the online movement. "Both sides owe us far better than this and the mayor [Boris Johnson] has stayed well away. That makes us a broad church with a shared goal".

The group is still in the organising stages, and it is unclear if any delay to the start of 24-hour Tube service will materialise. But TfL's spokesperson advised that station platforms are "not for political demonstration".

The potential protests by citizens, they said, "demonstrate how people recognise the Night Tube service is in demand".