A government Bill affecting trade unions has been described as the most sustained attack on workers' rights since the early 19th century in a letter signed by scores of academics.
More than 100 academics in industrial and employment relations from across the country have backed the open letter, maintaining that unions are too weak, having had their power diminished since the 1970s.
Under the Trade Union Bill, thresholds will be introduced for union strike ballots, employers will be able to hire agency staff during any action, and union subscriptions will stop being automatically taken from the payroll.
The academics said the UK labour market was already one of the most flexible and least regulated in the global economy, describing evidence supporting the Bill as "seriously wanting."
They warned that further undermining the bargaining power of unions would increase low pay and insecure terms and conditions among non-unionised workers.
Mark Stuart, president of the British Universities Industrial Relations Association, the professional body of employment relations academics, and professor at Leeds University Business School, said: "Instead of attacking trade unions in this way, the Government should be looking more seriously at how to engage and involve the British workforce and its representatives in rebuilding the UK economy and raising productivity through fairer and more supportive rights for workers."
Ralph Darlington, professor of employment relations at the University of Salford, said: "If unions find their ability to mount strike action is curtailed, one likely prospect is an increased tactical reliance by unions on so-called 'leverage campaigns' and 'citizen bargaining' - whereby unions use demonstrations, protests, boycotts, and social media campaigns to open up new lines of attack on the employers and its senior management, with the aim of getting shareholders, customers, suppliers and local communities to put pressure on the employers to back union demands."
The letter says the Government should be looking at how to engage with workers and raise productivity through fairer rights.
A Business Department spokesman said: "People have the right to know that the services on which they and their families rely will not be disrupted at short notice by strikes supported by a small proportion of union members.
"The ability to strike is important but it is only fair that there should be a balance between the interests of union members and the needs of people who depend on their services."