Jamie Reed, Labour MP for Copeland, spoke in support of airstrikes against Islamic State militants in Iraq, but said the government needs to be honest about how long the conflict may last.
He returned to the House of Commons to debate the issue with other MPs.
Parliament is due to vote on whether the UK joins airstrikes in Iraq at about 17:00.
The Scottish National Party has revealed its two Smith Commission members: Finance Secretary John Swinney and East Kilbride MSP Linda Fabiani.
SNP leader and First Minister Alex Salmond made the announcement that the two SNP members will sit on the cross-party commission, which is to look at strengthening the powers of the Scottish Parliament.
The Conservatives and Liberal Democrats have already announced their members.
"John Swinney and Linda Fabiani are two excellent and experienced advocates of the need for a significant strengthening of the Scottish Parliament's powers, so that it can deliver more for the people of Scotland.
"The Westminster parties vowed in the referendum that Scotland will get 'extensive new powers', and John and Linda will be constructive voices ensuring that this promise to the people is honoured in full.
"We also believe that there must be meaningful consultation with civic Scotland and all of those who have become engaged in the political process as a result of the referendum."
The latest episode of ITV Border's Scottish political programme, Representing Border, looks at the issues from Holyrood and Westminster that matter to the south of Scotland
Borders MP Michael Moore has been picked to take part in cross-party talks on more powers for Scotland.
The former Scottish Secretary helped put together the Edinburgh Agreement, which set the terms for the referendum. All five parties with MSPs in Holyrood will take part in the negotiations - but the Lib Dems are the first to announce their team. They claim they're the most prepared to deliver ambitious changes.
"I want to see a Federal United Kingdom I'm not sure we'll quite achieve that in one bound..not least because that's about how the rest of the UK wants to be part of that and theres a lively debate in England which I respect and want to keep on track with - however for Scots politicians, responding to voters last week we've got some serious challenges but I feel what we've set out is an ambitious set of proposals which can keep us in the United Kingdom but move the game on."
Lib Dem MP Michael Moore will join the negotiations to give Scotland more powers.
Lord Smith of Kelvin had been appointed by the three UK leaders to achieve a consensus on more powers for Scotland. He hopes to have two members from each party to "work together and agree the detail of what those powers should be".
Read more here.
Michael Moore part of Lib Dem team that will negotiate more powers for Scotland in Smith Commission. http://t.co/w9h0o2Lcx8
Keith Brown, MSP for Clackmannanshire and Dunblane, has announced his bid to be the Deputy Leader of the SNP.
Following Alex Salmond's resignation, Nicola Sturgeon has launched her bid to be the first female SNP leader.
The latest episode of ITV Border's Scottish political programme. Representing Border looks at the issues from Holyrood and Westminster that matter to the South of Scotland.
As the SNP continues to grow, doubling its membership since the referendum, today Ed Miliband wouldn't tell us how many members his party has in Scotland.
The Labour Leader said he knows he has work to do following the support for the Yes campaign. But at his party's conference in Manchester, he told our Political Correspondent Paul Brand he was proud of Labour's role in the 'No' campaign.