The law on industrial action - Strikes and industrial action

The law on industrial action

Industrial action is when employees take action against their employer because of a work dispute. This is usually organised by a trade union.

Types of industrial action include:

  • striking
  • picketing
  • action short of a strike, for example refusing to work overtime

In some situations, an employer might take industrial action. For example, a 'lockout' to stop workers from working.

Industrial action is usually a last resort when other ways of negotiating have not worked.

Employees, employers and trade unions must follow industrial action law, mainly covered by the:

  • Trade Union and Labour Relations (Consolidation) Act 1992
  • Employment Rights Act 1996

Official action

Official industrial action is when a trade union has followed all the legal rules. This includes holding a ballot for members to vote.

During official industrial action, employees are protected by industrial action law.


This is when employees take action by refusing to work.

Find out more about striking


This is when employees and trade union representatives stand outside a workplace to tell people why they are striking.

Find out more about picketing

Action short of a strike

This is when employees continue to work but withdraw some of their labour.

For example:

  • 'working to rule' – this means refusing to do work that is optional in their contract, for example refusing to work overtime
  • 'go slow' or 'slowdown' – this means deliberately slowing down their work
  • refusing to do a specific task or part of the job

If the trade union has followed a legal ballot process, employees are protected by industrial action law.

Action short of a strike does not usually break the work contract.

If you need more advice about contracts and pay during action short of strike, contact the Acas helpline.

Unofficial action

Unofficial industrial action is when either:

  • a trade union takes action without following the legal rules
  • employees take action that's not authorised by a union

If employees take unofficial action, they are not protected by industrial action law. However, they'll still have their usual employment rights.

Examples of unofficial action include:

  • secondary action
  • unofficial or 'wildcat' strikes

Secondary action

Secondary action is when workers take action in support of striking workers at a different workplace. This is sometimes called 'sympathy action'.

For example, refusing to cross a picket line, or refusing to handle goods or services from the employer involved in the dispute.

Unofficial strikes

A strike is unofficial when either:

  • a trade union strikes without following the legal rules – for example not holding a ballot
  • employees strike without involving their union – sometimes called a 'wildcat strike'

Find out more about strikes

If someone takes unofficial action

Employees who take unofficial action are not protected by industrial action law. This means they could be fairly dismissed for taking unofficial action. However, they'll still have their usual employment rights.

If an employer feels there's an issue with the employee taking part in unofficial action, they must follow a full and fair disciplinary procedure.

For example, if a delivery driver refuses to cross the picket line of a different employer, it's up to the driver's employer to decide whether it's a problem. If they feel it's a conduct or performance issue, the employer must follow a full and fair disciplinary procedure.

If you're considering taking unofficial action, you can:

Holding a ballot

To take official action, trade unions must get agreement from their members by holding a ballot.

The ballot asks members to vote on taking industrial action – for example, to strike, take action short of a strike, or both.

For the ballot to follow the legal rules, the trade union must:

  • hold the ballot before taking industrial action
  • give the employer 1 week's notice of the ballot starting
  • invite all eligible trade union members to vote
  • use a postal ballot, and follow voting paper format rules
  • share the vote tallies with everyone who was eligible to vote
  • tell the employer the result as soon as possible
  • have an independent ballot supervisor, if balloting over 50 members

For the ballot to be successful, the ballot must also meet voting thresholds which include:

  • at least 50% of eligible members must respond to the ballot
  • at least 40% of eligible members must vote yes if they work for an important public service

Taking action after a ballot

If a ballot is successful, the union has 6 months to take action. If the union wants to take action after that, they'll need to hold another ballot.

If action takes place without a legal ballot:

  • the union could face legal action or be fined
  • employees would not protected from unfair dismissal if they took action

For more about balloting rules, check:

Who can take part in industrial action

If there's a successful ballot, any employees in the 'bargaining unit' can take part in industrial action.

The bargaining unit is the group of employees the trade union can act or decide specific things for, through a 'collective agreement'. This includes:

  • trade union members who were asked to vote in the ballot – it does not matter if they voted, or how they voted
  • non-union members who cannot vote, but can join any official action

To check if a collective agreement is in place, check the employee's contract, or ask the trade union or employer. This could cover all employees in an organisation, or a smaller group doing similar work.

Trade union representatives can also take part in industrial action.

Find out more about who can take part in:

Dismissal and less favourable treatment

Employees who take part in an official strike and other industrial action have extra legal rights.

Less favourable treatment

Employers should not cause 'detriment' to anyone who takes part in official industrial action.

Detriment means someone experiences one or both of the following:

  • being treated worse than before
  • having their situation made worse

Examples of detriment could be:

  • their employer reduces their hours
  • they experience bullying or harassment
  • their employer turns down their training requests without good reason

Unfair dismissal

Anyone who is legally classed as an employee is protected by law from unfair dismissal if they take part in official action.

If they are dismissed for going on strike for 12 weeks or less, it is an automatically unfair dismissal.

If someone is legally classed as a worker, they cannot claim unfair dismissal. However, they might be able to argue that being dismissed because they went on strike was a detriment.

Find out more about unfair dismissal

Get advice and support

As an employee, you can talk to your trade union representative if you're a member.

If you're a member of an employers' association like the CMI or FSB, you can contact them for advice.

Employers and employees can contact the Acas helpline. We can talk through:

  • any questions about strikes and industrial action
  • your dispute and how we might help find a solution
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