David Cameron has ruled out mansion tax on high value residential properties if he is still leading the country after the general election in 2015.

The Prime Minister made the announcement as he launched the Conservative conference in Manchester.

He has long spoken against such a policy, although it still represents a plan of action for the Liberal Democrats.

Nick Clegg has hinted that the mansion tax on homes worth £2 million or more could feature among his party’s post-election coalition negotiations, but this is yet to be confirmed.

Going forward, however, Mr Cameron’s ruling on the matter could prove to be a major obstacle to any renewed coalition deal.

Speaking on the BBC’s Andrew Marr show, the Prime Minister insisted that his future tax policies would not punish people who generate wealth and save their assets responsibly.

“I have never been in favour of this idea (mansion tax). I think it’s a bad idea,” he said.

“Stamp duty yes, council tax yes, but I think wealth taxes are not sensible for a country if it wants to support wealth creation, wants to reward saving and people who work hard and do the right thing.”

Michael Fiddes, head of agency at Strutt & Parker, agrees with Mr Cameron, believing that the fundamental problem with the idea of a mansion tax is the blurring of lines between capital and income taxation. He said: “a tax levied annually on a capital asset, and not on disposal of the asset, can lead to inequity; there will be people who are asset rich and cash poor who will not be able to afford this tax”.

A flurry of policy announcements were made at the conference in Manchester, including the acceleration of the Help to Buy state-backed mortgage scheme and confirmation of no post-election tax rises.

Under the second part of the Help to Buy initiative, people buying a property worth less than £600,000 can get a loan of up to 15% of the price guaranteed by the government if they can afford a 5% down payment.

Several major lenders have already signed up to the second phase, which will be launched next week - three months ahead of schedule - as part of Conservative efforts to show they are tackling the cost of living.

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