He says only by Ministers taking direct control and ensuring deadlines were met was there any chance of thousands of customers being linked to the service within a reasonable timeframe.
And he has called for the disbanding of Connecting Devon and Somerset, the local authority-run consortium which has been managing the operation until now.
Last week it announced it was re-tendering the contract for the second, £35 million phase after BT, which was awarded the work for the first phase, conceded it could not achieve 95 per cent coverage by the end of 2017.
But Mr Liddell-Grainger, Conservative member for Bridgwater and West Somerset, said it was evident that CDS had been adopting a hands-off, rather than a hands-on approach.
“Whatever they might say about BT it is clear to all concerned that they have not been pushing BT hard enough, which is why unacceptable delays have been allowed to creep into the project,” he said.
“After speaking to a number of people including Communications Minister Ed Vaizey it has become abundantly clear that CDS has let down its member authorities and their council tax payers because they have not had the experience or the expertise to run the contract properly.
“On that basis our own hope lies in declaring CDS unfit for purpose, dissolving the consortium and handing the whole job over to the Government to manage.”