Northern Ireland and Wales cannot afford to be left behind by devolution talks involving Scotland, a former secretary of state for both countries warned.
Paul Murphy said It was important administrations in Cardiff and Belfast received fair funding in any financial settlement following the vote against Scottish independence and promise of further powers.
The Labour MP for Torfaen said first ministers Peter Robinson and Carwyn Jones needed to present a case to Westminster.
He said: "It is very important for the other two devolved administrations to talk about the implications of what happens in Scotland because we cannot get left behind."
The four parties in the Welsh Assembly have called for immediate talks with the Westminster Government about a "fairer funding agreement". Stormont First Minister Mr Robinson has said there should be discussions with his Welsh counterpart.
In a joint motion the Welsh parties called for talks with London to be completed by January and pressed for further devolution of financial powers to Cardiff Bay.
The Welsh First Minister has said there would be "very wide public support" for the "ambitious" reforms.
It came as MPs at Westminster debated the UK's constitutional arrangements following the rejection of independence in the Scottish referendum.
Devolved administrations are funded through a system known as the Barnett Formula based on a proportion of central government spending.
Northern Ireland receives around £10 billion a year in the block grant from Westminster to fund public services. The Welsh funding pot was recently put at around £14 billion.
Lowering the level of corporation tax, a levy on profits, is seen by Northern Ireland's business community and all the main parties as a key to revitalising the economy.
Prime Minister David Cameron has said: "Just as Scotland will vote separately in the Scottish parliament on their issues of tax, spending and welfare, so too England, as well as Wales and Northern Ireland, should be able to vote on these issues and all this must take place in tandem with and at the same pace as the settlement for Scotland."
Mr Murphy served as Northern Ireland Secretary under prime minister Tony Blair until 2005, a period when the IRA was in discussions about destroying its arms. He was also Welsh secretary.
The long-serving MP said probably the most pressing issue was finance and the Barnett Formula, since Scotland was likely to receive far-ranging taxation powers and a commitment that Barnett funding will not be reduced.
"It is very important that Northern Ireland and Wales get fair funding."
He said the Welsh and Northern Ireland premiers needed to meet to discuss taxation powers and possible wider devolution of powers. Justice and policing responsibilities have already been granted in Northern Ireland but not in Wales.
Mr Murphy added: "There is a lot of work to be done and the more they get together to be able to present a case to the Government, which appears to be absent with the focus on English votes for English MPs, the better."
MPs have begun debating further devolution to Scotland and its impact on the rest of the UK following last month's "No" vote in the referendum.
Leader of the House, William Hague, opened the debate telling MPs "the vow" on further devolved powers for Scotland "will be delivered whatever our deliberations about England".
They will also be considering other constitutional change throughout the UK including curtailing the voting rights of Scottish MPs in the West Lothian question. Labour has said it will not accept English votes for English laws.
The UK government published its plans for transferring more powers to the Scottish Parliament earlier this month.