WINNIPEG - Jack Layton kicked at Stephen Harper's closed-door campaign strategy and railed against alleged Conservative misdeeds Tuesday in a performance that overshadowed the NDP's latest policy pronouncement.

The New Democrat leader pre-empted a policy announcement on families to go over laundry list of scandals, including the latest revelation that the prime minister hired a senior adviser who had five fraud convictions.

His comments were among his strongest criticisms of government ethics since the beginning of the NDP campaign, which has focused heavily on issues and solutions.

Layton denied he was forsaking policy for politics in order to steer the national spotlight toward his party, which is locked in a pitched battle with Liberals for left-leaning voters.

"I think with these new revelations regarding Mr. (Bruce) Carson, with the fact the government went to court to block access to the Afghan detainee documents, with the fact we have the auditor general's report on the G-8 available but not being released, it's time to speak out about the fact this government is not being truthful and open with Canadians," he said.

The latest revelations that Carson, a former PMO staffer who is now under investigation by the RCMP for alleged influence-peddling, rated only passing mention by Layton on Monday as his campaign shored up shaky votes in southwestern Ontario.

The sense that there might be Conservative blood in the water over accountability and ethics, issues that brought the government down in a contempt-of-Parliament motion, seemed to take hold among New Democrats on Tuesday.

The reported expulsion -- and/or exclusion -- of real or perceived opponents from Harper rallies only added to the incredulous tone.

"Just because you have a different opinion, you can't walk into the room with the prime minister, that's wrong," Layton said.

"And every Canadian should be worried about that, especially when the people he is letting into the room have the kind of record Mr. Carson has."

Late Tuesday, the NDP put out a photo of one of the women ejected from a Conservative rally in London, Ont., who later attended a Layton speech in the same hall.

Layton said Awish Aslam, 19, a political science student, is an NDP supporter who just wanted to check out what the other parties were saying.

"We welcome Awish and all Canadians looking to build a better country," he told a rally in the riding of Winnipeg North late Tuesday.

The Conservative missteps came as Layton has faced increasing questions about the familiarity of many of the NDP's policy announcements, which have contained recycled promises from previous campaigns and ideas that have already been talked about, with the occasional tweak here and there.

"We're mixing the best ideas of the past with the new ideas of today," he said.

The prime minister acknowledged knowing that Carson had been convicted in one case involving two counts of fraud, but not in another case involving three. Layton said he doesn't believe Harper, and he claimed most Canadians don't either.

"Canadians are right to be asking -- if Mr. Harper wins this election, how long will it be until the next Conservative insider is charged with fraud?"

And just to emphasize the point, he repeated his entire condemnation in French rather than alternating between languages as he usually does.

The NDP's policy plank Tuesday centred on measures to help the so-called "sandwich generation" -- people who care for aging parents and young children at the same time.

One in four Canadians cared for a seriously ill member of their family at home in the last 12 months.

"For many, it's a labour of love. But it often means making deep sacrifices," he said. "Nearly half of those Canadians with loved ones at home are depleting their personal savings just to get by."

Layton is promising a retro-fit program to help families upgrade houses when elderly parents move in. It's modeled on an existing program in Manitoba and would provide forgivable loans to a maximum of $35,000.

He also pledges to expand the compassionate-care provisions under employment insurance by extending leaves to six months from six weeks.

The NDP also say they'd introduce a so-called caregiver benefit, similar to the existing Child Tax Benefit, to assist middle- and low-income households with the extra burden of caring for family members. It would be worth $1,500 per year.

In total, the NDP says the caregivers plan would cost the federal treasury $1.3 billion.