Can the time period for which a warning is active be "paused" when an employee goes on maternity leave and then "resumed" afterwards?
While an employee is on maternity leave they are still employed and their terms and conditions of employment continue to apply. The disciplinary procedure is therefore applicable throughout the maternity leave period.
There is a risk that "pausing" a warning while an employee is on maternity leave could expose the employer to a discrimination claim. By "pausing" the warning the employer is in effect extending it by up to a further 12 months. This may amount to less favourable treatment for a reason related to pregnancy and/or maternity.
If the disciplinary policy is contractual and does not make provision for the employer to "pause" a warning, it will not be entitled to do so and could face a breach of contract claim, as well as one for pregnancy and maternity discrimination.