Schools face the prospect of strikes this month as teaching assistants prepare to mount action over pay.

Classrooms across Brighton and Hove could be forced to close for strike days on November 17 or 25 if the city council fails to settle the row, which has been raging for ten months.

Two of the biggest public sector unions have balloted 700 teaching and general assistants - with 88.6 per cent of GMB members and 93.5 per cent of Unison members voting in favour of strike action.

The council today said it did not know how the action would affect its 70 schools.

More than ten months after negotiations started members are said to be angry at a pay offer from the city council which they say would give them up to seven weeks' less pay a year.

In a joint statement the unions described the offer as "an insult" to staff carrying out skilled work.

They said assistants had been undervalued and underpaid for a long time and their roles had changed dramatically in recent years to give them more responsibility.

Alex Knutsen and Mark Turner, branch secretaries for Unison and the GMB, said in the statement: "This is the first time either trade union has locally balloted its school members for strike action and the result is a clear indication of the anger and frustration they feel at the council's offer.

"If the council is serious in its pronouncements about fairness and equality on a general level, it will settle this matter as originally agreed with the GMB and Unison.

"Strike action is a very last resort, it should not be necessary, especially in schools, but will happen if the ruling political group continues to treat low paid women workers in such an arrogant manner.

"We call upon the leader of the council to personally intervene and honour the original agreement."

Tory opposition leader Garry Peltzer Dunn said: "I very much regret it has to come to this.

"I would have thought the administration would have attempted to keep the dialogue open as I would have expected the unions to do.

"Strike action is the last resort and nobody wins. I would have hoped that talks would continue. I think the administration has tried to simplify thestructure in line with other employees of the authority in a rather heavy-handed way. I can see it from the teaching assistants' point of view."

Changes in the way pay is calculated have been introduced by the council in a bid to ensure all employees are treated equally.

Instead of paying teaching assistants in special schools for 49.5 weeks of the year, they will be paid for 45.7 weeks, in line with other non-teaching school staff.

Union members fear they will lose out while the council deny this.

The authority said if it met the unions' demands it would face a £700,000 bill and some teaching assistants would earn more than newly qualified teachers.

GMB and Unison representatives were locked in talks with council leaders last night about the proposed industrial action.

The council's deputy leader Sue John said: "There's a basic principle about being fair to all of our employees and having a level playing field.

"The offer compares well with other authorities. We are concerned there has been some misinformation introduced into the campaign because we know 90 per cent of teaching assistants would be better off with this deal."

Coun John said the authority would be in discussions with head teachers about "the facts of the issue".

She said: "We are consulting with those directly affected so they can put contingency plans in place."

Green Party convenor Keith Taylor, said: "I am very disappointed it has come to brink of strike action.

"I understand and have every sympathy with the staff who have been forced into this position.

"The teaching assistants have our support, and I hope very much that we can avert a damaging strike.

"I am pleased to see staff are being graded properly for the work they do but I think for the council to subsequently link an increase in the rates for the job with a decrease in the weeks worked is where the problem lies."