Unison will tell the Prime Minister, members of his cabinet and MPs that many council staff have just a few pounds spare every week after paying increasing energy and housing bills and some were now being forced to cut back on food.

Unison members in England, Wales and Northern Ireland will start voting on Friday on whether to strike over a 2.45% pay offer which has already been rejected.

The ballot result will be known next month with the likelihood of a two-day all-out strike in early July, followed by escalating action, involving strikes of more than two days, if there is a yes vote.

Unison's head of local government, Heather Wakefield, said: "It is time that MPs faced up to the grim reality of low pay in local government and took action to support their constituents. Lobbying local government employers to come back with a better offer than the miserly 2.45% would be an important step in the right direction.

"Many of our members tell us they spent winter making tough choices between heating their homes and putting food on their tables. With the cost of everyday essentials like bread up a massive 44%, gas and electricity by 15% and petrol by 21% this is hardly surprising.

"Local government workers deserve to be fairly paid for the job they do. We would all suffer if teaching assistants, care workers, nursery nurses and social workers could no longer afford to do their jobs and voted with their feet."

Council workers covered by the pay claim include care home and home care assistants, housing and environmental health officers, refuse collectors, librarians, nursery nurses, social workers and school cooks.

More than 60% of those covered earn £15,825 or less, so a 2.45% would mean a rise of £32 per month.

Brian Baldwin, chairman of the employers, said: "Any settlement has to be affordable both to the taxpayer and councils while at the same time making sure that local government continues to be an attractive place to work. If the pay settlement is set too high, councils will be forced into making unpalatable choices between cutting front line services and laying off staff. Neither unions nor employers want either of these options."