Unison Scottish secretary Matt Smith was speaking in a Scottish Trade Union Congress debate on the economy on Tuesday.
'Many politicians are too ready to call for public sector cuts to 'allow the private sector to grow' This is wrong. Not only is the public sector not a drain on the economy - I don't recall a great boost to the private sector when the Tories under Margaret Thatcher cutback the public sector - but the opposite is true.
'During this election campaign we call on politicians and business to stop such false attacks on hard-working public service workers.'
Unison was speaking to one of five key demands from the STUC put out as a challenge to Scotland's political parties - to grow the public sector to act as a driver for economic growth.
Mr Smith said:
'The public sector delivers 22% of the overall GDP of Scotland. Equivalent to finance and business services and real estate combined, more than manufacturing and twice the size of the retail and wholesale sectors. Public sector workers contribute not only their services, but their taxes, and their spending power to Scottish economy. The double-thinking of politicians, businesses and economists has to stop.'
Unison accepts that the private sector needs to grow, and points out the current lack of capacity in Scotland's private businesses - shown up by the failure of Scottish PPP schemes to attract any meaningful competition. But that is in spite of not due to, the size of the public sector.