Senior executives from some of Britain's best-known businesses have hailed the current British government's economic policies, which they claim show that "the UK is open for business", in a move orchestrated by the Tories campaign team.

The top executives - including BP's CEO Bob Dudley and vice-chairman of West Ham United, the Conservative Peer, Baroness Brady - argue that keeping the Conservatives in power is the best way to ensure continued growth.

In an open letter to The Telegraph, the signatories, who had been approached by the party to add their names to the letter, said the Conservatives' economic policies have supported investment and the creation of jobs.

The letter has been signed by at least five former Labour backers including the chairman of Dixons Carphone and Talk Talk plc, Sir Charles Dunstone and former Dragons' Den star Duncan Bannatyne.

The business figures write: "We believe this Conservative-led Government has been good for business and has pursued policies which have supported investment and job creation."

"David Cameron and George Osborne's flagship policy of progressively lowering corporation tax to 20 percent has been very important in showing the UK is open for business. It has been a key part of their economic plan."

"The result is that Britain grew faster than any other major economy last year and businesses like ours have created over 1.85m new jobs."

"We believe a change in course will threaten jobs and deter investment. This would send a negative message about Britain and put the recovery at risk."

Today's #businessletter in the @Telegraph shows job creators support our long term economic plan. Labour's taxes will cost jobs.

— David Cameron (@David_Cameron) April 1, 2015

The Telegraph describes the letter as the "biggest ever endorsement by business leaders of a political party" - it states that it will "further undermine the economic credibility" of Ed Miliband and the Labour Party.

Labour's shadow business secretary Chuka Umunna responded to the open letter, saying: "No one will be surprised that some business people are calling for low taxes for big businesses."

"We don't believe, as David Cameron does, in more tax cuts for the richest in society - the priority is tax cuts for small firms, working people and saving our NHS," he said.

Mr Osborne told Sky News: "This is an unprecedented intervention in a British General Election. A hundred business people, employing over half a million people and leading some of Britain's best-known companies, from Primark to the Prudential and from BP to Britvic and Mothercare have spoken out."

"Their message could not be clearer. We have a Conservative economic plan that is working and is creating jobs and if we change course those jobs will be threatened and the recovery will be put at risk."

Other business leaders to put their names to the letter were Prudential CEO Tidjane Thiam, former head of Marks & Spencer Lord Rose, chairman of the Arcadia Group Sir Philip Green, and chairman of Bloomberg Peter Grauer.

Bloomberg was the venue Labour used for its business manifesto launch on Monday, which was overshadowed by a backlash against an advert that the party placed in the Financial Times.

A number of the firms quoted were quick to distance themselves from political allegiance to the party.

Lord Rose told Sky News it was an "implicit warning: don't tamper with what is working well."

Shadow work and pensions secretary Rachel Reeves said: "The letter to the Telegraph does not mention the Labour party at all and it's just about one policy: corporation tax."

"It does not mention membership of the EU, which is of course such a big deal to many large businesses or investment in infrastructure or skills but also it does not talk about the small businesses who are going to benefit from Labour's freeze, or cut, in business rates."

On Tuesday Labour pledged to reverse the final cut in corporation tax to pay for a reduction in rates for 1.5 million small businesses.

Shadow chancellor Ed Balls also promised smaller firms they would be the first to benefit from future tax cuts if Labour takes power.

Later today Mr Miliband is expected to announce plans to take a tougher stance on zero-hour contracts.

Under the proposal workers will be able to demand a regular contract after 12 weeks.