Barristers, solicitors, paralegals and all who work in the law are being urged to join a single trade union aimed at unifying the notoriously individualistic profession.

Following the failure of repeated attempts to sustain industrial action over cuts to fees and legal aid, several senior lawyers including Michael Mansfield QC have now endorsed the initiative.

At the start of their careers, lawyers choose mainly to become either solicitors, who represent clients and do most of the work outside court, or more specialist barristers, who deliver submissions in hearings. Separately, there are also legal executives. The advent of solicitor advocates is making those divisions obsolete.

In terms of militancy, the segregation is increasingly between those who work in criminal, legal aid or state-funded cases and those who take cases for better-paying commercial or private-sector clients.

Legal Sector Workers United (LSWU), a new branch of the United Voices of the World (UVW) union, has been founded with the aim of bringing together everyone including paralegals, solicitors, barristers, receptionists, interns, personal assistants, administrative staff, cleaners and security guards.

The UVW has already organised walkouts and strikes among cleaners, security staff and receptionists at the Ministry of Justice over demands for the London living wage. The LSWU will oppose what it says is the sector’s “poverty pay” and inequality and will campaign for the restoration of legal aid that was cut under austerity.

Previous attempts to unite the fissiparous profession have not been successful. The Law Society, which represents solicitors in England and Wales, accepts that the roles of professional bodies and trade unions are distinct. “Solicitors, like anyone else in a free society, are entitled to join a trade union,” a Law Society spokesperson said.

The LSWU points out that paralegals often do not earn even the London living wage of £10.55 per hour, while equity partners in some City firms are paid more than £2m per year.

Similarly, junior barristers earn as little as £12,000 per year and often take home less than the minimum wage after costs are deducted for a day’s prosecution, paid at a flat fee of £46.50. Low fees have already triggered action by barristers in recent years.

Franck Magennis, a barrister at Garden Court Chambers, said that in previous negotiations the Ministry of Justice had succeeded in playing solicitors off against barristers. “We need to create a union that unites people in different parts of the profession,” he said. “Having a single union to negotiate with the Ministry of Justice would make it much easier.”

Prominent lawyers are backing the new union. Mansfield said: “This initiative is long overdue. I was involved in an earlier effort in the 1970s which was far less ambitious and did not survive. This has the advantage of a far wider constituency of workers who are constantly at risk of exploitation and marginalisation despite their critical role.”

John Hendy QC, the chair of the Institute of Employment Rights and a leading trade union and employment law barrister, said: “The inequalities in income and in terms and conditions in the legal world are notorious and I therefore support the initiative to form the Legal Sector Workers under the banner of United Voices of the World.”

Jonathan Black, a former president of the London Criminal Courts Solicitors’ Association (LCCSA), said: “The launch of this organisation … will seek to bring about a common purpose across the legal professions and beyond. The law may be broken, but it can be fixed by ensuring the voices are heard, not only through the LCCSA but also through the LSWU.”

Lucie Wibberley, a criminal defence barrister at Garden Court chambers, said: “With the arrival of LSWU as part of the trade union movement, we see a new generation of lawyers, with a renewed sense of purpose and a vision for the future, determined to protect legal aid and all that it stands for.”