GLASGOW is facing a summer of discontent with rubbish collections set to shut down for weeks at a time in some of the most bitter industrial action in decades.

Tens of thousands of council workers are poised to strike over pay after the Scottish Government made a three per cent pay rise offer – a figure unions say is not enough.

Last night, union leaders vowed to shut down refuse collections in major cities at the height of summer. The dispute could see city and town centres left with bins full of unemptied rubbish.

Strikes would be timed to cause major disruption to flagship summer events such as Glasgow hosting the European Athletic Championships and the Edinburgh Fringe Festival.

Drew Duffy, lead negotiator for the GMB union, said a three per cent rise would give cleaning staff an increase of £250 a year – a significant drop from the fixed flat increase of £1,500 which the union is pushing for.

"[Finance Secretary] Derek Mackay may think that three per cent is a fantastic offer and that we should be grateful, but he's got the wrong idea," Duffy told our sister publication, the Sunday Herald.

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"Our members are the lowest paid in local government and they have been hammered in terms of pay for years, but now they've had enough.

"Many of them will just get £250 a year with this offer, which is derisory. We've been pushing for a flat rate increase of £1,500 to make sure those at the bottom get more.

"Over the next few weeks we'll ballot members on rejecting this offer because it's not good enough. Then, if Cosla and the government don't talk to us, we'll move to a full ballot on industrial action.

"It would be targeted summer industrial action."

The dispute threatens to become the most bitter industrial battle the SNP has had in its 11 years in power, and the clash comes as Nicola Sturgeon is set to address the opening day of the annual Scottish Trades Union Congress (STUC) in Aviemore on Monday.

Talks between local councils body Cosla and the GMB union, which represents refuse workers, cleaners, care home staff and janitors, broke down last week.

The union will ballot its 30,000 members on the three per cent pay offer in early May. A rejection of the government offer could then see a second vote on industrial action held in June.

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Duffy said strikes would then take place throughout the summer months and would involve cleaners, care home staff and janitors, as well as refuse workers.

He said the action would "cause massive disruption" during events such as the European Athletic Championships in Glasgow from August 2-12.

"It could shut down refuse in Glasgow for a week and we would have bins full on the streets during the championships," he said. "There would be rubbish piled up.

"We'd move the action around from Inverness to Glasgow, Dundee, Edinburgh and elsewhere."

However, Duffy said the union was "open to negotiation" and called on Mackay to step in.

"We've been told take it or leave it, but we want to get back around the table," he said. "Derek Mackay could and should intervene."

The Scottish Government is already facing the prospect of a strike by teachers.

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The EIS teaching union branded an offer of a three per cent wage increase “unacceptable" and said it would be prepared to walk out of the classroom if it wasn't improved.

However, a Scottish Government spokeswoman defended the pay offer made to public sector workers, saying: "We were the first administration in the UK to commit to lifting the public sector pay cap. Our pledge to lift the cap for all public sector workers is still unmatched across the UK.”

A Cosla spokesman added: "We hope that our trade union colleagues will recognise that in the current financial climate and with the budget settlement we received, we are making a fair offer to all our employees."