OTTAWA - While political operatives pick through the entrails of Monday's four federal byelections, there should be one troubling signal for all.

Just over one in four eligible voters cast a ballot as selected Canadians in Ontario, Saskatchewan and B.C., were given a chance to send a signal to their gridlocked House of Commons. Two of the four races - in Toronto Centre and northern Saskatchewan's Desnethe-Missinippi-Churchill River - had voter turnout of just 25 per cent.

A third race in Vancouver Quadra managed 27.9 per cent, and the Toronto riding of Willowdale was the participation leader at 33.9 per cent turnout.

Combined, the four byelections turned out just 27.9 per cent of the eligible vote, the lowest of any grouping of federal byelections in the last decade.

"I think it's really a decline in interest in general," said Barry Kay, a political scientist at Wilfrid Laurier University in Waterloo, Ont.

"I'm not sure there's truly a definitive answer, certainly not that's unique to (Monday's) results."

Hand-wringing over voter turnout is nothing new. Participation in the 2006 general election was 64.7 per cent, up from 61 per cent in 2004 but a far cry from the historical norm in the mid-70s.

Byelections always draw fewer voters, but Monday night's turnout is at least 10 percentage points below the norm.

The two 25-per-cent ridings rank among the five worst byelection turnouts since 1998, a span that covers 32 separate races.

The biggest byelection turnout in the last 10 years was in the May 2005 tilt in Labrador, when 53.4 per cent of eligible voters cast ballots. Liberal Todd Russell won and bolstered Paul Martin's shaky hold on a minority Liberal government.

The lowest turnouts of the last decade both came in 2002, under very different circumstances.

Liberal Massimo Pacetti won his north Montreal riding after just 22.9 per cent of the voters bothered to cast a ballot. Pacetti was running to replace Alfonso Gagliano, the former Liberal public works minister who resigned under a cloud to accept a post as ambassador to Denmark.

That same day, a fellow named Stephen Harper won his seat for the Canadian Alliance in Calgary Southwest, where just 23 per cent of eligible voters turned out. Neither the Liberals nor the Progressive Conservatives ran a candidate against the new Alliance leader, driving down voter participation.

In 2003, a Quebec byelection in Levis managed the third worst turnout of the past decade at just 23.5 per cent.