Ukip stately home tax aid plan announced by Shropshire candidate William Cash

He says it would help those struggling to preserve historic properties.

However, it comes in stark contrast to Labour's pledge for a "mansion tax" if the party wins May's General Election, which would place an additional levy on those with homes worth more than £2 million.

Mr Cash, owner of Spears magazine and son of senior Tory MP Sir Bill Cash, lives at Upton Cressett Hall, near Bridgnorth, and has revealed the issue is one of the reasons why he joined Ukip.

VAT was imposed on the renovation of listed buildings by George Osborne in the 2012 budget. He argued that leniency on listed building renovations allowed the owners of manor houses to install swimming pools without paying tax.

But Mr Cash said: "Our planning and tax policies should support, not discriminate against, the rich heritage of our built inheritance and the efforts of those who enjoy preserving it and sharing its custody with others and for future generations."

He said the burden of tax imposed on the "restoration classes" was leaving Britain's historic properties "crumbling away".

Upton Cressett Hall is a 15th century manor house with a moat, bought and restored by Sir Bill Cash in 1969. He now lives in a converted barn in the grounds of the hall, while son William has taken over the running of the grade I listed property.

Ukip has promised to exempt historic buildings from VAT at 20 per cent on building work, which would save wealthy owners of historic mansions and castles hundreds of thousands of pounds.

It would be replaced with a rate of five per cent.

However, critics have said the policy would potentially benefit some of Ukip's biggest manor-house owning donors, though a party spokesman said none had known about it or had asked for the policy.

He said the tax cut would help thatchers, stonemasons and carpenters, and many owners of listed properties are not wealthy.

He said Mr Cash was open about his link to Upton Cressett, owned in a family trust.

Mr Cash will stand for the North Warwickshire seat in the General Election.