David Cameron is being urged by a group of his own MPs to cool his party's approach to immigration amid claims it has become near obsession which is pandering to Ukip.

A new group, Conservatives for Managed Migration, is being launched by backbencher Mark Field in a bid to end the "hostile debate" over immigration and oppose the government's arbitrary cap on migrants.

With immigration being pushed up the political agenda, particularly by Nigel Farage's Ukip, Field believes real harm is being done to the party's image as it scrambles to keep up with Ukip's rhetoric.

"The relentless focus on immigration by the Conservative Party seems to the outsider to border on near-obsession. The implicit message to the electorate is that my Party is fundamentally hostile to those who were not born here, and deems the presence of settled migrant communities to be a mistake," he said.

"The rumbling threat of UKIP has only stiffened the resolve of mainstream parties to keep tough talk on immigration firmly on the front pages.

"The tone of debate suggests there is no middle ground between rabid, drawbridge-raising right-wingers and soft liberals bent on scrapping immigration controls.

"We must avoid hysterical reactions to the problems of the last decade, when migration did indeed drift out of control. Nor should we be trying to recreate a Britain as it was in the 1950s. Those who have or will come here are not numbers – they are people," he said.

The group will oppose the government's cap on migration, claiming it is not only unworkable but economically damaging.

"Government efforts to decrease numbers inevitably rest on keeping out many of the most desirable types of non-EU migrant, talented entrepreneurs, academics and business people," he said.

Field's group will aim to foster a " calm and reasoned discussion about immigration both within and beyond the Conservative Party."