Czech public sector unions threatened yesterday to call a rare nationwide strike unless the government agreed to raise wages before an October parliamentary election.

Unions say their members should benefit from a robust economy that saw overall average wages rise at their fastest pace in a decade in the second quarter.

They are demanding a 15-percent pay hike for teachers, and 10 percent for other state workers, saying the changes should be in place by Nov. 1.

Large-scale union protests are unusual in the Czech Republic - the last public sector walkout took place in December 2010.

Josef Stredula, chairman of the Czech-Moravian Chamber of Trade Unions, said members had decided to take action after the three-party, centre-left coalition government failed to reach an agreement on the rise during a debate on Monday.

"The Nov. 1 line is uncrossable for us," he told reporters. "We don't have a problem with a strike."

The unions will hold a rally on Sept. 14, and decide then on further steps if no serious agreement is reached, Stredula said.

Czech unemployment is the lowest in the European Union, at 2.9 percent according to Eurostat.

The pay gap between teachers and other highly-qualified employees is the biggest out of all countries in the OECD club of developed economies, according to the IDEA think tank.

Despite recent pay jumps, average hourly wages in the Czech Republic are less than a third of those in neighboring Germany.