But the confederation told Building that it was in everybody's best interests if further fragmentation of the industry was prevented. A spokesperson said that the confederation had no knowledge of the break-away plans but was aware that there is a debate involving some contractors about whether there needs to be a "Premier League" group to meet the needs of large contractors.
The spokesperson said: "The interests of all concerned would be best served if this function was to fall under the umbrella of the Construction Confederation as a further fragmentation of the industry's representation would mean we did not punch our weight with government."
To be a member of the MCG, firms need to have a contracting turnover of more than £300m a year, but some firms want the benchmark to be higher. They feel the agenda of the MCG is dominated by the smaller contractors, which do not face the same international issues, or have such a deep involvement in PFI.
Sir John Gains, chief executive of Mowlem and outgoing president of the Construction Confederation, is believed to be pressing the contractors to keep this new rival body – which could be called the International Contractors Group – within the confederation.
One source close to the talks said: "If the majors pull out of the ConCon, it could go bust. There are talks going on, and I'd say it was 50/50 whether they stay or go."
A Construction Confederation insider dismissed this claim. He said: "If the organisation was to lose the income of the larger firms we would restructure our provision of services to reflect our income."