Nurses could keep holding strikes “up until Christmas” if the current dispute is not resolved, the leader of the Royal College of Nursing (RCN) has told Sky News.

Pat Cullen, the head of the RCN union, was speaking as her members picket today – although the period of action is truncated after judges ruled the mandate to withdraw labour expired tonight.

But members will be reballoted after rejecting an offer put to them earlier this year, despite other unions accepting it.

“It is for the secretary of state to come back around the table and put a better offer on the table,” Ms Cullen told Sky News.

If this fails to materialise, Ms Cullen said the country could “see our nursing staff on picket lines up until Christmas. But we don’t want that”.

“We do need to bring this health service back from the brink.”