Prime Minister Stephen Harper has called four byelections for June 30, a date smack between a weekend and Canada Day.

Voter turnout, always low for byelections, may be even lower.

Given Canada Day, July 1, is a national holiday, many voters will be tempted to take the day off on voting day so they can go away for a mini-holiday, or perhaps kick-start their summer vacations.

Two of the byelections are in Alberta, a province where the Conservatives swept every riding but one in the 2011 federal election.

The other two are in Ontario, in seats vacated by a Liberal and New Democrat.

Those two ridings, Scarborough-Agincourt and Trinity-Spadina, in the next several weeks, will experience campaigns for the federal byelection, the Ontario provincial election and the fall municipal election.

Asked about the timing of the federal byelections in Ontario when two other levels of elections are occurring, Conservative cabinet minister Tony Clement told a reporter just outside the House of Commons, "First you complain there's no democracy, now you complain there's too much democracy."

The treasury board president added, "I'm fine with it. We have lots of volunteers."

Mulcair calls timing 'curious'

On Monday in the foyer of the House of Commons, NDP Leader Tom Mulcair called the timing of the byelections "curious." In French, he said many people will be leaving to begin their holidays and pointed out that in Alberta, Harper has had six months to call a byelection in the MacLeod riding, yet waited until now.

Conservative MP Ted Menzies resigned his southern Alberta seat in Macleod in November to become president and chief executive officer of CropLife Canada, a trade association for plant-life technologies.

Conservative MP Brian Jean, who represented the riding of Fort McMurray-Athabasca, stepped down in January, citing a desire to spend more time with his family.

The Conservatives anticipate hanging on to the two Alberta ridings but do not expect to win more than 10 per cent of the vote in each of two Toronto-area contests, said one senior Tory insider, who spoke on condition they not be named.

"The two Ontario ridings, I think the writing's on the wall on those," said the source, who picked Justin Trudeau's Liberals to win both fights.

The timing of the byelections and unusually long seven-week campaign period, were intended to steer completely clear of the June 12 Ontario election, the Conservative insider said.

Provincial, mayoral races underway in Ontario

In Ontario, the byelections will unfold against the backdrop of the hotly contested provincial election and a municipal election in the fall.

Toronto's Trinity-Spadina became vacant when New Democrat Olivia Chow — widow of former party leader Jack Layton — resigned to challenge Rob Ford for the Toronto mayor's job.

Stephen Lewis, an NDP luminary and former Canadian ambassador to the United Nations, endorsed party candidate Joe Cressy, who is fighting Liberal nominee Adam Vaughan, a city councillor, for the riding.

"Joe Cressy is a rare breed in politics: intelligent, compassionate, tough, principled," Lewis said Sunday.

In suburban Scarborough-Agincourt, Liberal stalwart Jim Karygiannis stepped down to run for a seat on Toronto city council in a ward that overlaps much of the federal riding.

It's turf the Liberals have held for a quarter century, making it Grit candidate Arnold Chan's to lose.

Harper did not call a byelection for the Ontario riding of Whitby-Oshawa, left without an MP following the recent death of Conservative Jim Flaherty, the former finance minister.

The riding was not part of the mix this time out of respect for both the family and the parties, since none has yet nominated a candidate, the senior Conservative said.