Suffolk’s element of council tax bills is set to increase by 2% in April – despite the ruling Conservative group’s pledge to freeze the tax when it was re-elected three years ago.

The county council is to put up its bills, which will work out at £17.50 a year for a Band B property (the most numerous in Suffolk), after the Chancellor told councils they could make this increase – specifically to fund social care – during last year’s Autumn Statement.

The county will also be taking just over £8m from reserves to make the books balance as it brings in £34.4m of spending cuts.

Cabinet member for finance Richard Smith said the ruling Conservative group was determined to maintain the freeze on general council tax rates.

However an expected increase in government support for adult social care had not come through in the Autumn Statement. Instead the Chancellor had given councils the option of raising their tax by an extra 2% to cover increase social care costs.

Mr Smith said: “It was clear this was what the government expected us to do, and really we had no choice. I can say the general council tax is frozen but this extra precept is being introduced.

“I know people will just see it as an increase, of course I can – but we were not left with any option.”

The increase will bring in an extra £5.4m – but the county had anticipated the costs of providing social care would rise by more than £8m.

That meant that an extra £3.5m would have to be taken from council reserves – on top of about £4.8m that had already been planned.

Mr Smith said this was planned to be a one-off raid on the reserves: “Overall we have about £42m in reserves. This is needed this year, but as you can see we cannot continue to do this year after year,” he said.

The council is planning to cut £80m from its budget over the next two years – so in 2017/18 it will be looking for £46m in cuts.

It is looking at a total net budget of £493m next year – down from this year’s net budget of £507m.

Labour opposition leader Sandy Martin said there were few surprises in the council’s budget proposals – the only thing they had been waiting for was the confirmation that council tax rates would increase.

He said: “The Council’s reserves have been increasing year on year. The Conservative Administration claim that they will be spending down some of those reserves in the coming year, but they made that claim last year, and the year before, and the year before that, and yet every year the reserves rise.

“The cuts in this budget will make the County less attractive and less competitive for businesses, and make Suffolk a harder place to live for our residents”.