London Underground has been given one week's notice to come up with a better pay deal or face further strike action from staff.

The RMT union said that it expected a new offer by next Friday in order to avoid more industrial action dates being announced.

Following a damaging 24-hour stoppage last week, workers are threatening to bring more chaos to the Capital throughout the summer.

The union's left-wing general Bob Crow secretary has justified his aggressive negotiating stance by insisting it has produced results for members.

And the union appears unconcerned at courting unpopularity with commuters by sticking to its demands for higher salaries and a shorter working week.

The RMT executive will meet next week to consider its position following the shop stewards meeting which agreed the new deadline.

"If the executive has not received satisfactory offers by Friday July 16, further days of strike action should be fixed," they said in a statement.

Regional organiser Bobby Law said London mayor Ken Livingstone had forced the deadlock by refusing to make more money available.