Cleaners at the Houses of Parliament have announced a fresh strike date in a row over pay.
The cleaners staged a strike in the summer
The Transport and General Workers Union (T&G) members want their pay rates of £5.20 an hour raised to £6.70.
A 24-hour walkout by 140 staff will take place on 9 November leaving MPs and House of Lords members to clean their own offices and toilets.
Nick Harvey MP, the Commons Commission spokesman, accused the T&G of bad faith and said a deal was being hammered out.
The T&G said the dispute would only be resolved if contractors who hired the cleaners were given more money.
The union has accused the parliamentary authorities of refusing to attend meetings to try to resolve the row.
'Overwhelmed with support'
Deputy general secretary of the union Jack Dromey said: "It seems inconceivable that unelected, privileged civil servants are blocking attempts by parliamentarians to get their cleaners a living wage."
He also said that they had been "overwhelmed with support" by MPs and Lords, but the cleaners had been left with no alternative.
Mr Dromey said: "Justice will only be delivered by Parliament playing its part together with workers and the contractors. Parliament must now act to end this shame."
The workers staged the first-ever strike at Parliament in the summer, when MPs broke up for their break.
Mr Harvey said the cleaners' employer Mitie had offered £6 an hour, an increase of more than 15%, and was prepared to discuss the other demands of the cleaners.
He accused the union of breaking off negotiations and threatening fresh industrial action before all the details of the proposed new deal had been received.