It is estimated that anything between 250,000 and one million workers are employed on zero hours contracts in the UK.

Employment law does not define a zero hours contract. In practice it has come to mean a contract for casual work, where the employer does not guarantee to provide the individual with any work and pays them only for the work actually done. Usually, the worker is expected to be available to work if called on by the employer. Workers are effectively on standby and are generally contacted at the start of each week and told how many hours they will be required to work that week.

The advantages for employers are clear: they do not have to pay staff when there is no work available for them; nor do they have to pay sick pay.

In addition, those working under such contracts are likely to be classed as workers rather than employees, which means that they have fewer statutory employment rights.

Some individuals like the flexibility of a zero hours contract. They can combine working with other activities such as studying, caring or travel and the option to refuse work on occasion.

The main disadvantage for workers is that they do not get paid when they do not work, so cannot rely on their pay and it may be difficult to apply for loans, mortgages, benefits and tax credits.

Workers on zero hours contracts already have some protection under the law; if they regularly work a large number of hours, a tribunal can decide that they are permanent employees and have the full range of employment rights. If they work part-time, they have the right not to be treated less favourably than comparable full-time employees.

Please contact us if you have any questions regarding zero hours contracts or if you would like to discuss alternative options. Taking legal advice at an early stage could prevent problems in the future.

• Ware & Kay's specialist, Gill Wilkinson, has extensive experience in all aspects of employment law.