The two remaining park and ride sites in Ipswich could close in three years’ time if there is not a substantial increase in the number of motorists using them.

Suffolk County Council has warned that it is not prepared to continue subsidising them at the current rate – and would be prepared to consider “mothballing” the parks at Copdock and Martlesham when the current contract with operators Ipswich Buses expires in November 2018.

The news immediately provoked hostility across the town – borough council leader David Ellesmere said it showed that the county was not being serious when it claimed to support the Ipswich Vision.

The two park and ride centres in Ipswich cost council taxpayers £712,000 a year in subsidies (£356,000 per site) – however their supporters say they bring much more value to the town centre.

Norwich has six park and ride sites, and Norfolk County Council this year signed a £32m contract with Konnectbus to operate them for the next five years – that means the subsidy amounts to more than £1m per site per year.

Suffolk cabinet member for Transport James Finch said: “Due to the relatively low cost of town centre cark parks, the simple fact is that there is a declining number of people using the Park and Ride service.

“In 2014, London Road averaged 365 cars a day and Martlesham averaged 416 cars a day. The indication is that this number has dropped much further during 2015, around 3.4%.”

Both parks have 550 spaces – which means that the London Road site was 67% full on average across the year, and Martlesham was 76% full on average across the year.

Mr Finch said: “Ipswich Borough Council has plans to increase car parking provision in the town centre. If there was a shortage of car parking in the town centre then park and ride would be an attractive option but it doesn’t appear that the current or future situation will offer the Park and Ride service as a financially viable operation.

“The County Council’s proposed budget asks challenging questions about how we manage and operate a range of services in the future.

“We must focus first and foremost on the most vulnerable members of society. This means that we do need to look closely at services such as Park and Ride which are not currently self-sustaining and where there may be alternative options available.”

Mr Ellesmere reacted with anger: “This is an absolute disgrace. The county council says it signs up to the Ipswich Vision and then the start looking at this kind thing.

“Then they try to blame the borough for reducing the cost of parking in Ipswich town centre. This just shows what the Tory county council thinks of Suffolk’s county town!”

There was also disappointment from Ipswich Central, which represents businesses in the town centre.

Its chairman Paul Clement said: “Whilst recognising the County Council’s need to find savings, I am extremely disappointed on behalf of town centre businesses that the prospect of closure of park and ride has come into the public domain without thorough prior consultation

“The wider economic benefits of Park & Ride must be taken into account before any final decision is reached. Even the risk of closure sends a worrying sign to businesses, their staff and their consumers.

“The new Vision Board, which includes the County Council, will need to urgently discuss ways in which a reallocation of funding can be used to support the car-borne user into our town centre.”

Ipswich MP Ben Gummer said he realised the county had to cut costs, but hoped it would invest in the town: “If you ask the question ‘would you begin park and ride now’ then the answer has to be no – and that is the question at the root of this dilemma.

“However, it is important that the County demonstrates its commitment to the town centre and uses some of the savings it will make to invest in the town and improve parking provision. I am pleased that they have been keen to do so in the discussions I have had with them.”