The Conservatives are today stepping up their campaign against the planned European Union constitution with a warning that it could result in more red tape for UK businesses.

Shadow chancellor Oliver Letwin will today say that regulations and restrictions on British companies could double if the constitution is passed.

At a Westminster press conference Letwin and shadow industry minister Stephen O’Brien will launch a new policy document entitled "The drivers of regulation".

It will outline five root causes of over-regulation, all of which, the Tories say, must be tackled and reversed if the "overburdensome flow of regulation is to be tackled effectively".

The Conservatives are also set to announce the formation of a new taskforce charged with cutting red tape in the UK.

Speaking yesterday to the British Chambers of Commerce conference, party leader Michael Howard also condemned the constitution's potential to damage private companies.

Working Time Directive

He pointed to the Working Time Directive as the "single most expensive regulation for British business in the last few years".

"More than 40 per cent of new regulations start in Brussels. And be in no doubt - if Europe were to adopt the proposed European Constitution that burden will go on rising," he told the business audience.

"Don’t for a moment imagine that the European Constitution is an esoteric issue about sovereignty – important though that is. It would have a real and practical impact on your business."

He added that the Constitution incorporates the Charter of Fundamental Rights.

"The rights under the charter are loosely drafted.  They include the right to strike, the right to so-called social protection, and the right for workers to have information and consultation within business.  

"It will be up to the European Court exactly what these rights mean in practice. 

"And if past experience is anything to go by, they will lead to yet more burdens on business – burdens British politicians would be powerless to stop."