Mandatory business rate relief for charities has increased but discretionary relief is all but unchanged, according to the latest data from the Department for Communities and Local Government.

Total relief provided to charitable occupations amounted to £1.52bn in the year to March 2015, an increase of £86m, or 6 per cent on the previous year.

Charitable business rate relief is worth 45 per cent of all rate relief, with most of the rest spent on empty premises and small businesses.

Mandatory reliefs for charitable occupation increased from £1.39bn to £1.48bn, and discretionary reliefs for charitable occupation increased from £43m in 2013-14, to £44m in 2014-15.

Andrew O’Brien, head of policy and public affairs at the Charity Finance Group, said the rising cost of the relief “demonstrates how charities are trying to meet growing demand for their services at a time when their finances are under significant pressure”.

He went on to say that the stagnation of discretionary rate relief shows “the pressure that local government is under and this makes any potential devolution of business rates extremely concerning”.

O’Brien said: “Charities are critical in building social capital and business rate relief enables charities to work across the country. We hope the government recognises this when it puts forward its proposals for the future of business rates.”

Business rate reliefs are the single most valuable tax relief the sector receives. Charities receive 80 per cent mandatory relief on all business rates, with the other 20 per cent at the discretion of the local authority.

The future of business rate relief remains somewhat uncertain. The exchequer secretary to the Treasury has offered reassurance that the devolution of business rates does not relate to the mandatory element of charity business relief. However sector bodies have said that this "does not definitively settle the issue".

Total business rate relief increased from £3.14bn to £3.36bn in 2014/15.

Empty premises mandatory rate relief, which is the second biggest relief, reduced from £988m to £947m in 2014/15.

The net cost of small business rate relief, the third largest, decreased from £591m to £580m in 2014/15.