Prime Minister Stephen Harper has taken a chopper tour of flood-stricken southern Manitoba but apparently his government doesn't see any need for NDP Leader Tom Mulcair to see the disaster zone for himself.

Mulcair is in Winnipeg, just as floodwaters are expected to crest in the southwestern part of the province. Mulcair told reporters during brief remarks Wednesday that more federal money is needed to help people in the flood-affected areas.

With the help of Premier Greg Selinger's office, Mulcair had arranged to get a briefing and a tour of a military command post that's co-ordinating the work of 500 soldiers who've been helping fill sandbags and shore up dikes along the swollen Assiniboine River.

Brig. Gen. Christian Juneau, commander of the third Canadian Division, had agreed to the tour, according to Mulcair's office.

All that was needed was a green light from Defence Minister Rob Nicholson.

Brandon stop sign flood - July 3, 2014

NDP Leader Tom Mulcair had planned to get a briefing and a tour of a military command post co-ordinating sandbags to shore up dikes along the swollen Assiniboine River. But late Tuesday, Mulcair was informed that Defence Minister Rob Nicholson had nixed the visit. (CBC)

Late Tuesday, Mulcair was informed that Nicholson had vetoed the visit. Nicholson's office did not respond to a request for an explanation.

'No reason' for minister to intervene: NDP

"It's disheartening to see the Conservatives play politics during a crisis," said Mulcair spokesman George Smith.

"This was a simple briefing that had been arranged with the military. There was no reason for the minister to go out of his way and intervene."

Speaking with reporters Wednesday, Mulcair blamed "partisan politics" and said it was never a problem in the past for political leaders to observe flood measures.

"This is a time you are supposed to put partisan politics aside, have everybody working in one direction to show support for the people in those communities and that's all we were trying to do," Mulcair said.

Mulcair said he wanted to make the tour to see what was happening on the ground, to thank people and to see what could be learned for avoiding floods in the area in the future. "That's what we do in our line of work," he added.

It's conceivable Nicholson doesn't want politicians getting in the way of relief efforts.

But there were no such qualms Sunday when the prime minister took a 20-minute helicopter tour of the flood zone, accompanied by Selinger and local MPs.

"Obviously, we are here to express our solidarity with people, as I know everybody is very concerned about the situation," Harper said after a briefing with emergency personnel at Brandon City Hall.

Selinger's NDP government has welcomed politicians of all partisan stripes who want to see the extent of the crisis for themselves.

On Wednesday, Selinger was asked about the decision to nix Mulcair's visit to the flood zone.

"The federal government makes its own decisions about who they can allow to be here. We think everybody needs to understand the gravity of the situation. But ... we're focussing on making sure we're in a position to make the best decisions as rapidly as possible to protect people and property," he said.

Selinger declared a state of emergency last Friday and asked for military assistance to help communities at risk of being submerged to prepare for the floodwater crest.

This summer's flood, triggered by torrential rain and water pouring in from Saskatchewan, could break records set during one of Manitoba's worst floods in 2011.

with files from CBC News