Unison Scotland said in the past fortnight, it has welcomed more than 1,300 new members, with a significant proportion coming from education and early years’ establishments, where the union has a pay ballot running.
A spokesman for the union said its organisers pointed to several factors behind the increase, not least the fear of job losses and poor pay deals as a consequence of the Scottish Government’s spending review.
The Unite union said it had seen thousands of new members join up in Scotland since the start of the year. Its Scottish secretary, Pat Rafferty, said the spike was no coincidence.
“People are realising that the only remedy for boosting their pay and helping them to make ends meet is through trade unions,” he said.
Louise Gilmour, the GMB Scotland secretary, said its membership levels have “consistently grown” over the past 12 months.
"Just last month, recruitment was 20 per cent higher than the month before, and a massive 70 per cent higher year on year,” she said.
"Working people are being squeezed by this cost-of-living crisis and are fighting back in the best way they can – by joining a union and organising themselves.
"As long as GMB continues to make work better for our members, we will keep growing our union.”
With the prospect of swingeing cuts to the civil service workforce, another union that has seen strong growth is the Public and Commercial Services Union.
Over the past week alone some 639 members have joined. A spokesman said that rate was twice the weekly average.
As well as general rise in membership levels, more unions are seeking out affiliation with the Scottish Trade Unions Congress (STUC), a step that helps with training, recruitment and organising strategies.
One such union is the Pharmacists’ Defence Association (PDA), which represents more than 2,500 pharmacists across Scotland, and has been seeing its member numbers grow every year without fail since its establishment in 2003.
“The issues we’re dealing with are burnout after Covid-19, longer working hours, poorer conditions and depressed wages,” explained Maurice Hickey, the PDA’s policy officer.
Roz Foyer, general secretary of the STUC, said a trend that intensified during Covid-19 was continuing as rising bills and prices hit home.
“Since the pandemic and during the cost-of-living emergency, more and more workers are seeing the value of being part of our trade union movement,” she said.
“The STUC has seen growth in many sectors across the country. Just as importantly there is a growth in activity among existing members. Unions representing some of the most precariously employed and overworked staff throughout Scotland – our hospitality sector, healthcare and transport workers – have been fighting and winning for their members.”
It comes as the RMT union said it was “extremely likely” that Scotland would see more 24-hour rail strikes if talks between bosses and union continue to fail.
The latest talks to end the strike broke down, with RMT boss Mick Lynch accusing the UK Government of blocking a deal, a claim it has denied.