Boris Johnson's aides are drawing up plans designed to break the "stranglehold" of trade unions, The Sunday Telegraph can disclose.

Downing Street is examining proposals to bolster the rights of non-union members in the workplace as part of a bid to reduce workers' reliance on unions for "vital protections".

They include legislating to enshrine the rights of employees to be accompanied to grievance and disciplinary meetings by an external lawyer or representative of a body other than a union. Currently the law only requires employers, including schools, to allow staff to be joined by a trade union representative or colleague.

The move comes as staff at 74 universities across the country conduct a 14-day strike over pensions, pay and conditions. It follows a month of walk-outs on the South Western Railway franchise which caused major disruption in December.

Ministers have already announced plans to introduce "minimum service requirements" for rail services so that trains continue to operate in the event of a strike, in a move likened by the RMT to the actions "authoritarian regimes".

Now it can be disclosed that the proposals are part of a package of measures being drawn up by the Government to curb a perceived "stranglehold" of unions on workers in a range of sectors.

Number 10 is considering plans to amend the Employment Relations Act to give workers a legal right to be accompanied to disciplinary meetings by an external figure other than a union representatives.

A Conservative source said: "The unions have a stranglehold on workers, particularly teachers.

"We think all employees should be entitled to proper representation in disciplinary processes, not just those who have unionised. Nobody should find themselves forced to join one out of fear they will miss out on vital protections."

The proposals to amend the Employment Relations Act were recently set out in a paper by Edapt, a body that provides legal support to teachers. The firm warns that, while all workers should have "equal employment rights under the law", the existing legislation fails to give non-union members the right to be accompanied to formal meetings by "reasonably qualified companions" such as a lawyer or representative of an organisation such as Edapt.

"Statutorily, the chosen companion during grievance and disciplinary hearings may by a fellow worker, a trade union representative, or an official employed by a trade union," states the Edapt paper, published in December.

"Such accompaniment rights are often extended to investigatory meetings also. Any other request for accompaniment from a companion not in one of the categories above can be refused by the employer. The employer is free to have whoever they choose present to support, including a legally qualified person."

Edapt said that, in practice, schools generally allow their representatives to accompany teachers to disciplinary meetings. But Tory sources claimed that the current phrasing of the law gives union members an unfair advantage over other staff.

Aides to Mr Johnson are studying the paper, by John Roberts, the firm's CEO. Number 10 is understood to agree with the suggestion that teachers should have a choice of who accompanies them to grievance and disciplinary hearings, rather than being potentially restricted to bringing along a trade union representative.

Mark Lehain, the founder and former principal of Bedford Free School, who supports the plan, said: "This is an idea that has been floating around government for several years and I'm pleased that it now appears to be gaining some traction."

Mr Lehain, a former trade union representative, said: "This change would be great for employees across the economy and would bring the law in line with recent cases and most other countries."