Barring certain exceptions, yes. In order to claim unfair dismissal in terms of performance, an employee must have worked for a certain period of time:

• Before 06 April 2012: One year.
• On or after 06 April 2012: Two years.

It is only then that an employee is entitled to their main/ordinary unfair dismissal rights.

However, probation does not mean that employers can simply do what they want! Employees on probation do have the right not to be dismissed on grounds that could be deemed discrimination relating to matters such as age, sexual orientation, or religious belief. In some cases, for example whistleblowing, dismissal is automatically unfair even without any qualifying period. In these and other situations, the employee is entitled to make a claim.

However, that said, employers dealing with disciplinary or performance issues during a probation period, particularly one that could result in termination of employment, will want to be able to demonstrate that organisation’s grounds for its actions were genuine. Employers will be in a much better position to demonstrate this if they have conducted (and recorded) a proper/thorough investigation and given the employee an opportunity to explain their version of events.

You can find out more about probation periods here.