The shoes, some old and used, some brightly coloured and gay, lined the Whitehall pavement across the road from 10 Downing Street, attracting the surprised attention of some passersby.

Each of the 150 pairs represented a victim of the Troubles – some killed by the British army or the Royal Ulster Constabulary, some killed by the IRA, some by loyalists and some on the streets of Dublin or Monaghan in 1974.

Róisín McHugh was four when her father, Mick McHugh, was shot dead at his house near Castlederg, Co Tyrone in January 1997 by the Ulster Freedom Fighters. Dr McHugh, who is a GP in Surrey, said: “We grew up without him. That space was never filled. I have three children of my own now, they will never know their grandfather.”

Her father’s death has been investigated by the Historical Enquiries Team. The weapon that killed him had been used to kill three others. Links between his killers and serving or past members of the security forces were found too. Collusion, the team said, “was likely”.

She rarely talked about his death with English neighbours, "bar close friends", she told The Irish Times. When she did, they were "understanding, but quite surprised".

Usually, however, she did not speak of it, “it’s too painful”.

Speaking just a short distance from the Cenotaph which commemorates Britain’s war dead, she said: “We do not have a Remembrance Sunday. We are just told to forget, and that it is all in the past. Well, it isn’t really in the past.”

Paul O’Connor of the Pat Finucane Centre said Christmas brought back memories for the families of all victims, whether they died at the hands of the IRA, loyalist paramilitaries or British forces.

“We tend not to do any case work in December. The closure of the Historical Enquiries Team this month is particularly insensitive. We have got reports that we have not passed on to the families.”

The Set The Truth Free campaign, which has already displayed the shoes in Dublin, Derry and Belfast, is pressing for a full independent inquiry into all deaths of the Troubles where the facts are not known or contested.

Meanwhile, relatives of Seán Dalton remembered a man who died in an IRA booby-trap bomb when they went to a neighbour’s house in Creggan in Derry in August 1988 concerned because they had not seen for days.

The man had been kidnapped by the IRA, who had booby-trapped the house to kill RUC officers. It became known as the Good Samaritan bombing. However, the RUC had information days in advance that a bombing was planned on the estate.

Following the street display, the group, led by John Teggart, who speaks for the families of 11 people in Ballymurphy in West Belfast who were shot dead by British paratroopers over three days in 1971, shortly before Bloody Sunday, met Westminster MPs.