* Social Democrats promise tax cuts for workers, other incentives
* Party vows to tax big banks' assets
* For opinion polls table click on
By Robert Muller
PRAGUE, June 17 (Reuters) - The Social Democrats, the senior partner in the Czech Republic's ruling coalition but trailing in the polls, will try to lure back voters before the October elections by offering tax cuts for workers while tightening control of big business.
The party unveiled its election programme days after Prime Minister Bohuslav Sobotka said he would step down as leader of the country's oldest party in an attempt to reverse its slide in opinion polls.
In its programme, the party promised to cut taxes for employees, extend holidays to five weeks, raise the minimum wage to at least 16,000 crowns ($685) a month by 2022 and other incentives.
It also repeated a pledge from previous elections to introduce progressive taxation on big banks' assets and to clamp down on tax evasion by big business conglomerates.
In an attempt to shake things up, Sobotka proposed this week that his more popular and eloquent foreign minister, Lubomir Zaoralek, should lead the party's campaign into the Oct. 20-21 general election.
Zaoralek said on Saturday that the country needed consensus at home to make progress.
"The Left will not be convincing if it will not honour national interests," he said, adding that the party could also borrow the slogan "to help and to protect" from police cars.
Although the government has presided over a growing economy that helped it deliver the first balanced budget in two decades, the Social Democrats have slipped in the polls behind their main rival and coalition partner ANO.
All recent polls have shown ANO leading the Social Democrats, in some cases by a double-digit margin.
ANO was founded and is chaired by billionaire and former Finance Minister Andrej Babis, who has attracted voters with his managerial approach to governing and with his image as a political outsider.
The parties, together with the Christian Democrats, came to power in a centre-left coalition in January 2014 and are on course to becoming the first government in 15 years in the central European country to finish its term. ($1 = 23.3500 Czech crowns) (Reporting by Robert Muller; Editing by Adrian Croft)