ISS maintains the Jubilee, Northern and Piccadilly lines

Transport and General Workers' Union (TGWU) members also lobbied parliament as they begin their ballot on Tuesday.

Cleaners fear Tube Lines' contractor ISS plans 204 further redundancies in addition to 100 job cuts last autumn.

ISS said: "Our use of technology and the fact that we are maintaining high standards of cleanliness has enabled us to relocate a number of staff."

ISS is contracted by Tube Lines to clean and maintain the Jubilee, Northern and Piccadilly lines.

Our members will do everything they can to resist these cuts Tom Chinnery, TGWU

A spokesman for ISS would not confirm whether any further job cuts were planned.

The TGWU said that if further cuts were made it had "no doubt at all that cleaning standards on the Tube will plummet - and passengers will suffer".

The union's senior regional industrial organiser, Tom Chinnery, said: "London's passengers are entitled to ask why Tube Lines can get away with putting its profits before the safe running of three major tube lines.

"Our members will do everything they can to resist these cuts."

Maintain standards

MPs will put down an Early Day Motion opposing the cuts in the House of Commons on Tuesday, calling for minimum cleaning standards to be introduced on the Tube.

The ISS spokesman said the company was "disappointed" that the union had decided to ballot its members.

"We will continue to have dialogue with the unions and our staff whilst maintaining the current standards of cleanliness," he said.

Tube Lines also expressed regret over the ballot but said: "Any question relating to possible redundancies or redeployment of ISS cleaning staff is a question for ISS."