Protesters stormed the council chamber and called on the Mayor of Barnet to resign during a debate on halting library cuts.

The meeting descended into chaos after opposition Labour councillors called for a halt to £2.85m cuts to Barnet Borough Council’s libraries and a new consultation on the service’s future at the authority’s budget meeting last night.

Dozens of library campaigners, trade unionists and other activists had gathered outside Hendon Town Hall before the meeting, waving books and placards and shouting for the libraries to be saved.

In the absence of Councillor Danny Seal, the Conservative administration was left without its majority of one, meaning Barnet Mayor Councillor Hugh Rayner had to use his casting vote to push through measures including the budget.

But during a vote on a Conservative amendment to Labour’s motion, the Mayor used his casting vote to vote against his party by mistake, and then withdrew it.

Library campaigners stormed the chamber in anger, shouting “this is outrageous” and calling on the Mayor to resign.

Cllr Rayner left the chamber and protesters refused to leave, leading to confusion over whether the meeting would continue.

After 20 minutes, Cllr Rayner re-entered the chamber and resumed the meeting, using his casting vote to defeat the Labour motion to halt library cuts and launch a new consultation.

Conservative councillor Reuben Thompstone, chairman of the children, education, libraries and safeguarding committee, said the authority had been open to alternative suggestions and that the consultation had provided space for this.

Cllr Thompstone also slammed Labour for politicising the “emotive issue” of library cuts.

Liberal Democrat councillor Jack Cohen criticised the Conservatives for having a “distinct misunderstanding of what makes a community tick”.

Cllr Cohen said: “Public libraries are where you are a citizen, not a customer.”

Labour councillor Anne Hutton argued that a “complete rethink” was needed.

Cllr Hutton said: “There’s absolutely no need for this hasty decision. They could start by asking what people want in a 21st century service instead of just asking what cuts they prefer.”

Councillors were also presented with a petition signed by more than 9,000 people opposing library cuts by campaigner Alasdair Hill.

Mr Hill told the chamber: “Libraries are the temples of civic society. They go beyond books.

“More 2,000 consultation responses have been submitted. This is despite the galling question asking residents which options they prefer – close, close or shrink. Limiting the response may produce the data the council wants but it flies in the face of open and transparent democracy. Why can we not say we disagree with all options?

“We the petitioners and voters do not see any merit in any of the proposals nor do we see the consultation as anything other than a deeply flawed and misleading process.”

Mr Hill, the Liberal Democrat parliamentary candidate for Hendon, urged the council to “return to the drawing board” and find other ways to fund the service.

A decision on the future of the libraries is set to go to a committee meeting in the summer.