The political situation in Northern Ireland is at its most fragile for years and will be tested further by the prospect of greater devolution in the wake of the Scottish referendum, Ivan Lewis has warned.

The shadow Northern Ireland secretary hailed peace there as one of Labour's "greatest historical achievements".

But he stressed it was vital not to become complacent and called on David Cameron to act to end the current stalemate.

He also announced Labour would be setting up an independent commission to look into the country's economic problems - it has had the highest rate of benefit claimants of the 12 UK regions for 49 consecutive months.

Speaking at Labour's annual conference in Manchester, his home city, Mr Lewis said: "When history is written it will record that our movement created the NHS, the welfare state and the minimum wage.

"But alongside those monumental achievements should always be peace in Northern Ireland.

"It is one of the greatest historical achievements of our movement, and we should never ever forget it."

He cited the G8, the World Police and Fire Games and the UK's first ever City of Culture in Derry-Londonderry as examples of progress.

But he also noted the upsurge in dissident republican activity over the past two years and accused the executive of failing to move forward on legacy issues, including flags, parades and the past.

Mr Lewis urged the Prime Minister to take action, working with the Irish Government and US administration, and said Labour would support that process.

He also called on Northern Ireland's political leaders to face up to their responsibilities, adding: "Working in partnership does not require friendship or even forgiveness for past wrongs, but it does require mutual respect and a willingness to build mutual trust.

"Good leadership is about mobilising your supporters and delivering on bread and butter issues.

"But great leadership requires you to sometimes walk in the shoes of your former foes and say difficult things to your own base about the need for compromise.

"Northern Ireland's peace process urgently needs great leadership from all parties in the executive.

"This leadership will be tested even further in the debate about the nature of devolution across the UK in the aftermath of the Scottish referendum.

"This will undoubtedly have profound implications for Northern Ireland."

The shadow minister said Labour was committed to ensuring the voices of its people are heard in that debate as well as in relation to the cost of living crisis through the new commission.

It is to be co-chaired by Professor Deirdre Heenan, pro-vice chancellor at the University of Ulster and Colin Anderson who is chief executive of ASG advertising and design agency in Belfast.

They will be supported by a panel of experts and produce a final report by the end of February with recommendations to help shape Labour's plans for Government.

Mr Lewis went on: "Growth still lags behind most of the UK, inequality is above average and the private sector needs rapid growth.

"In both communities there is too much alienation caused by a lack of opportunity and aspiration.

"This is not unique to Northern Ireland but the stakes are higher as people are at risk of exploitation by paramilitary organisations and political extremists."