Refuse collectors in Utrecht are going back to work at the end of a seven-day strike in which tonnes of rubbish piled high in the city’s streets.

Unions have warned council workers will go on strike other municipalities in the coming weeks in an ongoing dispute over pay.

The FNV union is demanding a 12% increase for its members, while the Dutch local government association NVG has offered 5% this year and 3% next year.

Work to start clearing piles of festering rubbish bags from the streets of Utrecht began on Wednesday morning, but the backlog means some bins, such as food and garden containers, will not be emptied for another two weeks.

‘We have taken action with a clear goal and we have had a lot of support and understanding from the locals,’ refuse worker Stijn Kerkhoven told RTV Utrecht. ‘If you go on strike, you have to clean up afterwards. We have no problem with that.’

Utrecht’s alderman in charge of public services, Linda Voortman, said it was important that talks continued to resolve the dispute. ‘When we started the negotiations we said what we proposed wasn’t a final offer. We need to see if there is room for manoeuvre.

‘But on the other hand, we’re saying they need to move as well. 12 per cent for all staff will cost a lot of money. We need to build schools, plant trees and provide services for elderly people from that money as well.’

The FNV has said more local stoppages are due to take place in The Hague, Emmen, Dordrecht and the Betuwe. Council staff in Amsterdam and Almere and regional transport workers also went on strike earlier this week.

Altogether more than 100 strikes are planned during February, including shop workers in Rotterdam, social enterprises in Arnhem and medical taxi services.