They are the smallest councils in the country with the fewest powers, part of the small print on most council tax bills.

But maybe not for much longer. With higher-tier authorities struggling to maintain services and restricted in raising council tax, parish councils are stepping into the breach by taking over services that might otherwise be cut.

They are also charging for doing it. The average band D precept charged by parishes in England has risen by more than 6% in each of the past two years. This is in spite of last year’s warning to parishes by communities secretary Sajid Javid that they should restrain themselves and not overspend.

Unlike higher-tier authorities, parishes can raise their precept by as much as they wish without a referendum. However, supporters of town and parish councils insist that the threat of council tax capping among larger councils is not the only reason for parishes taking over services such as street cleaning, refuse collection and even libraries.

Justin Griggs, head of policy and development at the National Association of Local Councils, says parish councils are often better placed to provide services and keen to take on more. 'The squeeze on spending in some areas is accelerating this, as principal local authorities are having to consider the discretionary services they provide,' he says.

The option of using parishes to circumvent capping is certainly appealing to some higher-tier authorities. On May 4, councillors will be elected for the first time in four parishes in central Swindon with libraries among the services they could take over from the borough council.

Swindon, a unitary authority, has already devolved street cleaning, grounds and footpath maintenance, and the emptying of community bins to some existing parishes. Council leader David Renard says in some cases they do a better job than Swindon does in unparished parts of the town, partly because parish councils are not facing severe financial pressures.

An ongoing review of library services is likely to mean the borough only continues running five of its existing 15 libraries, with some of the remainder passed to parishes. 'We are capped for council tax,' says Renard. 'Parish councils are immune to demand-led services such as social care.'

Across England, parish precepts rose by 6.3% in 2017/18. This compares with 6.1% last year and 3.3% in 2015/16. In Swindon, the average band D council tax, including the social care precept, rose by 10.35% this year when parish precepts are included. Without parishes, the increase was 4.99%, just below the figure requiring a referendum.

Haydon Wick, in the north of Swindon, raised its precept by 50%, from £34 to £51. Parish clerk Terry Powell says the precept is relatively small so a percentage increase can give a false impression. But it would not be a surprise if parishes are asked to take on more non-statutory services in future. 'If the parish council chooses not to do it, then the borough council will say they’re not going to do it either,' he says

Swindon’s opposition Labour group describes the transfer of costs to parish councils as a “back door” increase in council tax and claims residents were denied the opportunity to approve the changes. But Renard says these were one-off precept rises that should not lead to ministers putting a spending cap on parishes.

According to the National Association of Local Councils (Nalc), about 250 parish councils have been created in England since 2000. This includes five set up last year and two in Waveney, Suffolk, that are also being elected for the first time on May 4.

In Waveney, the average band D council tax rose by around 9% when parish precepts are included. The district council insists the creation of a town council in Lowestoft and a parish council in nearby Oulton Broad was not an attempt to avoid capping.

In the main, Waveney’s parishes run services traditionally associated with parish councils, such as footpaths and play areas, although Lowestoft is taking over the town’s theatre. Only parishioners in the areas where new parish councils were created saw significant increases in precepts, says the district council.

Last year, the Government stepped back from requiring parish councils to hold a referendum if they wish to exceed a council tax cap set by ministers. Sajid Javid told MPs that parish precepts were being kept under review, but the government expected parish councils to 'clearly demonstrate restraint when setting increases that are not a direct result of taking on additional responsibilities'.

An increase in parish precepts means that, in some areas, households are paying almost as much council tax to their parish as to their district authority. In Twyford, Hampshire, a band E household now pays 85p to the parish council for every £1 paid to Winchester City Council, compared with 61p two years ago.

Twyford parish chairman Waine Lawton said the parish council is raising about £90,000 through the precept compared with £50,000 five years ago. The extra money helped pay for improvements to the parish hall, but the council is also maintaining footpaths and carrying out other functions that used to be performed by the city or county council. 'More and more is falling on our plate,' he says.

Nalc points out the lion’s share of parish council funds come through the precept, whereas higher-tier authorities receive the majority of their funding from government grant.

According to Justin Griggs, the expansion of parish council duties is helping to tackle a ‘democratic deficit’ in parts of the country. Councils should be upfront with residents as to why they are charging higher precepts, particularly when they are taking on work that used to be done by higher-tier authorities.

'There is a growing tendency for council leaders to be honest about the pressures they are under and the role parishes can play,' says Griggs. 'We will continue to make the case for parishes to be engaged with local people and explain how services are funded.'