Staff are in dispute with the charity Addaction, saying it has broken a pledge to keep wages in line with NHS rises since it was commissioned by Wigan Council to run these services.
Unison general secretary Dave Prentis and Angela Rayner, the current shadow education secretary and Labour deputy leadership candidate, joined striking workers and other protesters ahead of this month’s full council meeting.
Unison North West regional organiser Paddy Cleary said: “As the commissioning authority, we feel the council should step in and resolve this. "They’ve been sitting on the fence so far but we think they could apply more pressure to have this sorted."
Nearly 30 rehab workers in Wigan and Leigh walked out last Thursday after their dispute with the London-based organisation - which now goes under the name of We Are With You - took a back seat over the Christmas and new year period.
But the grievances that led to 11 days of walk-outs last year remain the same.
And anger has heightened after it was discovered that £140,000 had been spent on the rebrand from Addaction to We Are With You which the demonstrators say would cover the costs of bringing the wages into line.
As far as the rebrand is concerned, a spokesperson We Are With You, said: “We are proud of our service in Wigan. It is a warm, non-judgemental space which helps people to make healthier choices.
"Anyone can walk in and will be seen by a member of staff on the same day, with the latest Care Quality Commission report giving the service a rating of ‘Good’.
“We know only a minority of people who need support for drug, alcohol and mental health issues in the UK are actively engaging in treatment.
"We need to do everything in our power to change this. So, for the past 18 months we have been talking to our staff and the people who use our services across the UK.
"This research has shown that building a warmer, more personal brand will enable us to help more people overcome the barriers to accessing support.
"When tested, three times as many people surveyed said they would choose We Are With You compared to Addaction. We hope this will help more people to start a new chapter in their lives.
“The cost of the rebrand is a very small portion of our overall budget, with no local service being impacted by it.”
On the industrial action the spokesperson added: “We have listened to and understood our staff’s concerns and made a new financial offer which we think is fair and sustainable.
"We are clearly disappointed the majority of staff have rejected this and further action is going ahead.
"Separately, we are awarding all staff across the whole charity a two per cent salary increase in the next financial year. This is true for all our services, from Cornwall to Wigan, to the north of Scotland.
“We are committed to finding a solution that is fair and sustainable for our staff, clients and the whole community and will continue to work with our staff in Wigan and Leigh to achieve this.”