Teaching assistants in Brighton and Hove are set to strike on Thursday after union members overwhelmingly rejected a last-ditch offer aimed at ending their pay dispute.

At a packed meeting of Unison and GMB members at Brighton Town Hall yesterday, only three out of 324 Unison members voted to accept the latest deal from the City Council.

The GMB also expects overwhelming support for strike action when the result of its ballot is announced today.

Dave Prentis, the general secretary of Unison, told the predominantly female crowd he had refused to meet council bosses.

He said: "This revised offer is an absolute disgrace and there is an arrogance that I have never seen before from an employer."

The council had written to its 1,000 teaching assistants offering them one-off bonuses of up to £450 in an effort to resolve the dispute.

The latest offer came on top of an overall package the council said was worth between £7.23 and £9.90 an hour and would mean an increase in the total pay bill from £8.8 million to £10.5 million over three years.

Mr Prentis added: "I think we've got to get one message to the council - we will not sit back and be abused.

"No one wants to take strike action but we cannot shy away from the last resort because if we are treated badly we cannot give the service our children deserve."

The unions are sending a leaflet to every household in Brighton and Hove outlining their reasons for the strike.

However, the council called on assistants not to take industrial action and claimed the union had stoked up the dispute with misinformation.

It has also set up a special hotline for teaching assistants who want to "clarify the nature of the industrial action".

Incoming chief executive Alan McCarthy said: "We know that feelings are running high but we do not believe inconveniencing thousands of parents will solve anything."