​Second home owners are to be targeted in one of the major tax rises planned by the new government, raising hopes it could free up properties for local families in the Westcountry.

Prime Minister David Cameron signalled that a new rate of capital gains tax would take aim at people who buy holiday homes as an investment, while supporting those who back business. Capital gains tax is predicted to increase from its current level of 18 per cent to 40 per cent or even 50 per cent, depending on the level of income tax people pay.

Some industry experts predicted a “rush” of properties on to the market, as owners sought to avoid the rise, which is among a number of tax and spending changes expected in Chancellor George Osborne’s emergency budget, which it was announced yesterday would be held on Tuesday, June 22.

Details of £6 billion of spending cuts to be made this year will be set out next week, while all spending decisions taken by Labour ministers since the start of the year are to be reviewed.

The coalition has warned that it is looking to tax non-business capital gains at rates similar to those applied to income. The government said there would be “generous exemptions for entrepreneurial business activities”, but it is thought the new band would still apply to gains made on most shares and, crucially, property. In opposition, the Conservatives rejected calls from campaigners and politicians from Cornwall, Devon and Somerset for action to be taken to limit the impact of second homes on the region.

Rows of properties standing empty for much of the year, including long stretches of the winter, have been blamed for the demise of many village services, with shops, post offices and pubs unable to survive just on the trade that comes when the properties are occupied at weekends and the summer season.

One in 10 homes in parts of the region is owned by people whose main residence is not the area. Recent research showed that South Hams in Devon has the highest concentration of second homes outside of London, with the properties accounting for 10 per cent of all housing, followed by North Cornwall at 9.6 per cent.

Truro-based nationwide property finding company County Homesearch said the proposed tax change could trigger sales of second homes in areas where local people have struggled to get on the property ladder.

Founder Jonathan Haward told the Western Morning News he backed the rise, but appealed for an amnesty period of 18 months before its introduction which would lead to “a lot of second homes coming on to the market”.

“There would be a lot of fluidity in the market, with more properties coming on to feed local demand,” he said. “It will free up properties for local people in traditional places like Cornwall and Devon, where absentee owners contribute to the closure of schools, pubs and local businesses.”

People who continue to own second homes should also be subject to higher council tax, he added. “If they are not going to be part of the community, they can pay for the destruction caused.”

Mr Cameron made clear that he thought second home owners should pay more tax when they sell up. “There is a very big difference between the capital gains that someone pays on, say, a second home – which is not necessarily a splendid investment for the whole economy – there’s a difference between that and actual investment in business assets,” he said. “So we’ve said that we’re going to look at a different rate between those two things and that helps actually again the fairness agenda. That helps us achieve the goal of lifting tax allowances, so we take more people out of tax. I think people will understand.”

Richard Copus, regional spokesman for the National Association of Estate Agents, said he did not think the proposed rise would have a significant impact on second home sales, because most people saw them as long-term investments. He said: “The thing to remember is that the average age of people buying second homes is in their 40s and 50s. People tend to hang to their second homes for quite a long time. It’s not really going to make a lot of difference, unless some of those people were thinking of selling them. It will put a few more houses on the market, but only a handful.”

However, other industry experts disagreed. Ronnie Ludwig, a partner at chartered accountants Saffery Champness, said: “We are likely to see a rush of sales of second homes and share portfolios where people are in a position to realise a gain, and anyone with investments should think about their portfolio sooner rather than later.”

James Davies, investment research manager at financial advisers Chartwell Group, said clients are urged to think about selling assets. “Those who have made gains on property and are in a position to sell might be able to benefit from the current lower tax rate, but it is hard to sell a house quickly.”

Estate agent Knight Frank said they had received a number of calls from second-home owners thinking about making a quick sale but said it was “far too early” to tell if there would be a rush of property sales.

Liam Bailey, head of residential research, said: “The initial response from the industry has been to suggest there will be a mass sell-off of investment and second homes. This is unlikely. There will be some people who will look to dispose of assets sooner rather than later, to avoid the prospective tax. However most investors in residential property are in the market for the long term.” With interest rates so low, rental yields have become a more important driver of demand rather than short term capital price growth.”