Contractor claims European procurement procedures were broken when contract for Parliament building was awarded to Bovis.
Sir Robert McAlpine is suing the Scottish Parliament for £4.3m after it lost out on the project management contract despite tendering the lowest bid.
The contractor said it was taking legal action over "alleged breaches of European procurement procedures in connection with the award of the contract for the Scottish Parliament building".
Bovis won the contract with a tender of £6.2m after it was readmitted into the tendering process. It had originally been dropped because its initial budget was thought to be too expensive. Sir Robert McAlpine’s bid for the project was £4.8m.
Sir Robert McAlpine decided to serve the writ after a request for a meeting with the Scottish Parliament met with “no reasonable response”.
The Scottish Parliament corporate body said: “Sir Robert McAlpine are claiming for the sum of £4.31m, a substantial sum that would have to be found form the public purse if this action is pursued and is successful.”