LJUBLJANA (Reuters) - Slovenian police went on strike on Monday demanding a wage hike of about 15 percent, the first of a wave of public sector walk-outs this week piling pressure on the government.

Nurses will stop work for two hours on Tuesday and teachers will strike on Wednesday, union leaders said, both groups pressing for higher wages in the build up to national elections expected in June.

Around 200 police officers protested briefly outside the government building, blowing whistles and holding up a drawing of Prime Minister Miro Cerar with his hands over his ears - suggesting he was not listening to their demands.

Some officers could still be seen on the streets of Slovenia’s capital Ljubljana - police spokeswoman Vesna Drole said the force would have enough staff available to ensure security.

The action came less than three weeks after around 30,000 public servants staged a one-day strike, demanding higher pay amid robust economic growth.

The government expects the economy to expand by 3.9 percent this year versus 4.4 percent in 2017, mainly on account of higher exports and investments.

But business groups, including the Chamber of Commerce, have warned that excessive wage hikes would hurt investment and growth and lead to higher taxes.

The center-left government has said most wage demands are not acceptable as they are not justified by productivity and could threatened fiscal consolidation.

The government hopes to end 2018 in a budget surplus of 0.4 percent of GDP after running a deficit of some 0.8 percent of GDP last year.

Radivoj Urosevic, the head of the Police Trade Union, told Reuters on Monday the officers were undervalued and they deserved more to reflect the hours they worked.

“The average gross monthly wage of a policeman is about 1,400 euros and we demand that the average wage be increased by some 200 to 220 euros,” he said.