Dissident republicans stepped up their efforts to kill a Catholic police officer after Deputy First Minister Martin McGuinness visited an injured policeman in hospital six months ago, MPs have been told.

Martin McGuinness labelled the attack on the 27-year-old officer as “spiteful and selfish” and infuriated dissident republicans when he visited the officer after surgery.

The officer, who joined the PSNI in 2004, suffered serious leg injuries when a bomb exploded under his car near Castlederg in County Tyrone.

Martin McGuinness made an unannounced visit to the injured policeman in Altnagelvin Hospital two days after the May attack to show his support for the PSNI.

The action infuriated dissidents in the groups, which vowed to renew efforts to kill a police officer as a response.

Last week MPs were briefed by a top MI5 officer.

He told members of the Northern Ireland Committee at Westminster that the threat against nationalist PSNI officers was at its highest level ever and that more planned attacks were in the offing.

One MP told the Belfast Telegraph: “The intelligence officer told us that the hospital visit by Martin McGuinness to the officer in May had struck a deep chord I suppose you would call it with the dissidents and they saw it as a very poignant symbolic act of defiance by the Deputy First Minister and they were determined to respond to it by eventually murdering an officer”.

Dissidents saw it as a very poignant symbolic act |of defiance

The injured officer, who is from the Omagh area, was based in Enniskillen and had left his home at Spamount near the border to report for night duty when the deadly undercar bomb detonated just seconds into his journey.

His life was saved by local people who managed to haul him from the vehicle before it was engulfed in flames and destroyed.

Assistant Chief Constable Judith Gillespie said at the time: “He has serious leg injuries and will take some time to recover.

“He has had surgery and it is expected that he will make a full recovery.”

She added: “He will be affected both physically and mentally but he is very determined to get back to work.”

Since the hospital visit Martin McGuinness has been involved in other highly publicised contacts with security personnel.

In July he told Army Chaplain Rev David Latimer, a Presbyterian Minister in Londonderry, that he would pray for his safe return from Helmand Province in Afghanistan.

Major Latimer the Minister of First Derry Presbyterian and Monreagh church in Donegal went to the war zone as a member of Northern Ireland’s Territorial Army medical unit.

He said he had received a good luck message from Mr McGuinness before he left which he described as “remarkable”.

“It confirms to me that what has happened in Northern Ireland is not phoney, it’s real,” the Minister said.