The State would have “huge difficulties constitutionally” in blacklisting “cowboys” who failed to complete a public sector construction contract before being awarded another, the Dáil was told.

Minister of State for Public Expenditure Brian Hayes acknowledged that the pricing of building contracts had become “very competitive” and subcontractors “can be stung” in the process.

However he told Fine Gael TD Patrick O’Donovan that “there would be much legal doubt and uncertainty as to whether the State can be involved in effectively blacklisting groups of individuals”.

Mr O’Donovan said there was a problem in the tendering process and subcontractors were “being screwed wholesale”. He said “excessively low” tenders were being submitted to county councils and Government departments “without any regard to . . . what is realistically deliverable in the market”.

Halfway through the contract, the contractor “goes belly-up, leaving local subcontractors in the lurch”, then another contract might be awarded to the same contractor in a different local authority.

The Limerick TD said the authorities could not carry out a proper background check on the contractor’s experience “to decide that he is a cowboy, having burned subcontractors previously, and exclude him from the process”.

Mr O’Donovan said the Construction Contracts Bill did not go far enough in establishing a certification process whereby subcontractors “must be paid in full before the next contract is awarded or before the last tranche of funding is drawn down”.