SWANSEA MP Geraint Davies has hailed the "nail in the coffin" of plans to reform the Welsh Assembly's electoral system.
The Government's Green Paper was supposed to reduce the number of constituency AMs to 30, and increasing the number of list members to the same amount.
This would have meant that Welsh Assembly constituencies were not "coterminous" — or the same as — Westminster seats.
Mr Davies used an adjournment debate in the House of Commons to attack the absence of "consultation or collaboration with the Assembly itself", something he branded "a complete disgrace".
He told MPs: "It showed a great lack of respect for the blossoming new democracy that we have in the nation of Wales, with a Welsh Government doing very good things and the road of devolution moving forwards.
"Where important decisions can be made locally by the people they affect most, that is what should happen. It was very unfortunate, to put it mildly, that the Prime Minister showed such disrespect to the leader of the Welsh Assembly Government."
The Green Paper also proposed five-year terms for the Assembly, something Mr Davies said he was "minded to support".
He added: "We need to move forward with effective democracy. It would help to have seats covering the same area for Assembly Members and MPs. Obviously, that could change in the future.
"It would be good to have stability in our relationships with constituents and for decisions increasingly to be made where they have the greatest impact."
In response, Wales Minister Stephen Crabb confirmed the Government would "not now take forward the Green Paper proposals on Assembly constituency boundaries".
He added: "The decision not to proceed with changes to Assembly constituencies does not mean an end to all the proposals in the Green Paper. We do not intend to let the significant work we have already undertaken go to waste."