Julian Fantino was greeted Monday in the House of Commons by opposition demands that he step down — but how much of a political liability the veterans affairs minister may be for the Conservative government remains to be seen.

Smelling blood in the water, the third-party Liberals have launched slick online ads to capitalize on the outrage that followed the auditor general's critical assessment of how Veterans Affairs has been treating mentally ill ex-soldiers.

One such ad, which features the ex-soldier who successfully fought the government over disability pension clawbacks, says: "Veterans fought for us. They shouldn't have to fight their own government."

Both the opposition New Democrats and the Liberals piled on during question period Monday — Fantino's first since auditor general Michael Ferguson tore a strip off the government for making soldiers with post-traumatic stress wait up to eight months to find out if they're eligible for treatment.

Fantino, who was in Italy last week attending commemorative Second World War events while controversy raged at home, brushed aside the criticism.

Opposition Leader Tom Mulcair called Fantino's recent absence from the Commons an act of "cowardice," and wondered aloud why he continues to have the confidence of Prime Minister Stephen Harper.

Minister's Italy trip 'dereliction of duty': NDP

"He showed dereliction of duty by fleeing the country," Mulcair said during question period.

"Will the minister — for once — do the honourable thing and resign?"

Liberal House leader Ralph Goodale was more blunt, saying Fantino has lost not only the confidence of the opposition parties, but former soldiers and the Canadian public as well.

"There is no trust or credibility left; will the minister simply stop the travesty and resign?" said Goodale, who later urged Harper to "fire this failed minister."

Through it all, Fantino stuck to his question period notes and rattled off a laundry list of steps the government has recently taken to improve mental health benefits and access to services for ill and injured soldiers.

"While the opposition resorts to exploiting veterans, fear-mongering and mud-slinging, we on this side of the House are continuing to make real, tangible improvements," he said.

Those improvements, however — announced in the run-up to Ferguson's scathing report — are now under the microscope.

On Nov. 23, just days before the report's release, a parade of federal cabinet ministers unveiled $200 million in new money to improve access for veterans, open additional operational stress injury clinics and enhance research and training.

Senior PMO staffer to serve as Fantino's interim chief

Background information provided during the announcement said there would be an up-front investment of $18 million in the clinics, with a further $152 million to flow throughout the lifetime of the program.

A published report last week said it could take up to 50 years for that money to be distributed, since veterans in their early 20s will require services for the rest of their lives.

Some of the cash, earmarked for additional counsellors and mental health first aid, will be spent over five years.

Under repeated questioning in the Commons on Monday, Fantino refused to clarify the numbers, which both opposition parties said had been fudged to make the government look good with an impressive dollar figure.

The Conservatives earned similar criticism a few years back when they announced $2 billion in improvements to their new veterans charter without saying it would be portioned out over several decades.

More recently, the revelation that $1.13 billion in budgeted funds went unspent at Veterans Affairs over nearly eight years has been dogging the government for weeks.

The Conservatives say they've poured an extra $5 billion — over and above what the Liberals were planning to spend — into veterans programs, but don't point out that some of that cash ended up as "lapsed funding" that went back to the federal treasury.

Meanwhile, Fantino is getting a new chief of staff.

Stephen Lecce from the Prime Minister's Office will act as Fantino's interim chief of staff while staying on at PMO.