Industrial action is when workers 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 against workers. For example, a 'lockout' to stop workers from working.
Industrial action is usually a last resort when other ways of negotiating have not worked.
Workers, 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
- Employment Rights Act 2025
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 on taking industrial action.
Workers are protected by law when taking official industrial action.
Striking
This is when workers take action by refusing to work.
Picketing
This is when workers and trade union representatives stand outside a workplace to tell people why they are striking.
Action short of a strike
This is when workers continue working 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, workers are protected by industrial action law.
Taking 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 – for example instructing members to strike without holding a ballot
- workers take action that's not authorised by a trade union
If workers 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, workers might refuse to:
- cross a picket line and enter the workplace
- 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
- workers strike without involving their trade union – sometimes called a 'wildcat strike'
If someone takes unofficial action
Workers 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.
Employers must follow a fair disciplinary process before taking action against a worker involved in unofficial action.
If you're considering taking unofficial action, you can:
- talk to your trade union representative for advice
- contact the Acas helpline to talk through your options
Holding a ballot
To take official action, trade unions must hold a ballot for their members.
The ballot asks members to vote on taking industrial action.
To follow the legal rules, the trade union must:
- hold the ballot before taking industrial action
- give the employer one week's notice of the ballot starting
- invite all eligible members to vote
- use a postal, electronic or in-person ballot
- share the results with everyone who was eligible to vote
- tell the employer the result as soon as possible
- have an independent ballot supervisor, if more than 50 members are voting
For the ballot to succeed:
- at least 50% of eligible members must respond
- more members must vote in support of industrial action than against it
A trade union does not have to hold another ballot if either:
- the type of official action changes
- the action lasts longer than expected
Taking action after a ballot
If a ballot is successful, the trade union has 12 months to take action. If they want to take action after that, they'll need to hold another ballot.
If action takes place without a legal ballot:
- the trade union could face legal action or be fined
- workers would not be protected from unfair dismissal if they took action
For more information about balloting rules, check:
- the Code of Practice for industrial action ballots on GOV.UK
- holding a ballot on GOV.UK, including how to complain about a ballot
Who can take part in industrial action
If the ballot is successful, workers in the 'bargaining unit' can take part in industrial action.
The bargaining unit is the group of workers the trade union negotiates 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, either:
- check the worker's contract
- ask the trade union or employer
This could cover all workers in an organisation, or a smaller group.
Trade union representatives can also take part in industrial action.
Dismissal and less favourable treatment
Workers taking part in an official strike and other industrial action have extra legal rights.
Less favourable treatment
Employers must 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:
- they experience bullying
- they experience harassment
- their employer turns down their training requests without good reason
- they are overlooked for promotions or development opportunities
- their employer reduces their hours without good reason
Unfair dismissal
Anyone with the legal status of employee is protected from unfair dismissal if they take part in official industrial action.
Someone is not likely to be an employee if they're:
- an agency worker
- a casual worker
- on a zero-hours contract
If someone has the legal status of worker, they cannot claim unfair dismissal. However, they might be able to claim that dismissal for taking part in industrial action was a detriment.
Find out more about unfair dismissal
Get advice and support
As a worker, you can talk to your trade union representative if you're a member.
You can contact an employers' association for advice, if you're a member. For example:
- the Chartered Management Institute (CMI)
- the Federation of Small Businesses (FSB)
Employers and workers 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