The revelation came during an employment tribunal launched by Dave Smith against the contractor which is due to last until Friday.

An agreed statement of facts by Carillion (previously John Mowlem), subsidiary Schal International and forerunner Tarmac confirmed that Smith was blacklisted but denied legal responsibility.

Carillion claim Smith was not directly employed by them and that they bought the two subsidiary companies – Mowlem and Schal – after they were involved in blacklisting.

Smith is claiming £175,000 in lost earnings in the wake of the blacklisting scandal which was exposed in 2009.

The tribunal heard that between 1999 and 2004 Mowlem paid £20,444 to the Consulting Association which ran the blacklist.

Smith said: “The period in which I found it hard to obtain any continuous stable work tallies exactly with the period in which the Consulting Association and its subscribers began to obsessively catalogue my working life and trade union activities, namely the period from 1998 until 2001.

“After Carillion and Mowlem started to blacklist me, in the tax year ending April 2000 my total income was £12,884.  I was a qualified engineer and during one of the longest building booms this country has ever known, my children were on milk-tokens.”