Business in the Commons is usually decided by the Government, but there are a set number of days given over to opposition parties. With the Lib Dems in government, the DUP is the second-largest opposition party and as such they get to determine the business on three days per session. On one of these DUP days last week the Commons debated air passenger duty and the legacy of the Troubles.
There was modest interest from English, Scottish and Welsh MPs in APD, less so in Northern Ireland's past.
In a three-hour debate only one MP who is not directly involved, either as their party's spokesman or as a member of the Northern Ireland affairs committee, made a speech.
Labour's Kate Hoey was the one exception, but her 40-odd years in England have done little to soften her Belfast accent, or her unionist leanings.
This lack of interest from MPs enhances the perception that the Commons regards the work of the peace process as complete.
The debate was a vivid demonstration of the many ways in which it is not. Perhaps it is too much to expect MPs who are not from Northern Ireland step into the lion's den and express opinions on what Alasdair McDonnell called "a murky past".
Observing the debate felt almost like intruding on private grief, as Jeffrey Donaldson, William McCrea and others spoke of the deep sense of loss still felt by the victims of violence. The debate fell on the 20th anniversary of the Shankill bombing.
"Whether innocent victims were murdered by those IRA bombers or by the Ulster Volunteer Force gang known as the Shankill Butchers ... or whether the victims were Protestant or Roman Catholic or of other faiths or none, it does not matter," Donaldson said.
"There cannot be equivocation between the innocent victims of terrorism and those who perpetrated those acts of terrorism."
Mark Durkan expressed equal solidarity with the victims of Shankill bombing and the Greysteel attack, "and all the others who lost loved ones, sometimes in lonely deaths that are not remembered in the commemorations of the landmark atrocities of the Troubles, because they, too, have their feelings touched or stirred by commemorations such as today's and by debates such as this".
He added: "If we do not have the truth about the dirty war, we will be settling for a dirty peace. If we do not have the truth about the viciousness and nastiness of all the violence that took place from all the paramilitaries, we will be selling future generations a false narrative about the experience of the past."
Towards the end, MPs began to file into the empty chamber as the House prepared to move on to APD. Those that were listening would have heard Theresa Villiers express hope that Richard Haass will help overcome "the power of the past to affect current events".
She recommended that politicians here take heed of the Queen's words in Dublin Castle in 2011, and find a way to "bow to the past, but not be bound by it".