Simon Hart MP is putting pressure on the Welsh Assembly Government to announce a decision on the Maidenwells by-pass near Pembroke.
He has been lobbying the Welsh Transport Minister to announce a decision about the project for months.
In his most recent letter, Ken Skates AM stated that a decision was expected in July – but nothing has been said yet.
Mr Hart said: "Many Maidenwells residents are very keen to see this long planned by-pass come to fruition and the Welsh Assembly Government has been dragging its heels for years."
The contract to design the project has been awarded following a public consultation, and the preliminary designs as well as the planning application and ecology and geotechnical surveys have all been undertaken.
A local public inquiry in to the scheme was held on 17th November 2015 and it's the result of the inquiry which is yet to be published by Welsh Government.
Mr Hart added: "Until a decision is made, work cannot start on the scheme. It is now 9 months since the inquiry took place and the Welsh Assembly needs to pull its finger out."
In a letter to Mr Hart dated 21st June, Mr Skates wrote:
"My officials have received a copy of the Inspector's Report following the Public Local Inquiry and I expect to receive advice on this matter shortly.
"I anticipate a decision being announced in July, once I have had the opportunity to fully consider the Inspector's Report."
Simon Hart MP
House of Commons
15, St John St
or 0207 219 3000