You can rest assured that there is currently no requirement for employers to provide staff with time off to vote. Instead, it is up to them to plan their trip to the polling station in their own time. Therefore, if individuals do wish to take time off work to vote you would be within your rights to require them to book this as annual leave.
Staff may try to argue that they have a lawful right to vote and whilst this is true, there is nothing to say they should receive time off work to do this. Although there is a right to reasonable time off work to participate in ‘public duties’ you should understand that this is limited to specific activities such as jury service or trade union involvement.
Having said this, given the circumstances and potential consequences of December’s general election, you may want to allow some flexibility to avoid any unrest at work. You should also bear in mind that employees who work night shifts, or have caring commitments outside of work, may struggle to find time to attend a polling station. Therefore, showing a degree of leniency may go a long way to fostering strong employee relations.
If you do decide to allow staff time off to vote, then you should make it clear whether individuals will be paid for this time. It is important that this is clarified from the outset to prevent any wage disputes further down the line.
It is also vital that you remain consistent, as allowing some individuals time off to vote but not others may result in grievances and potentially even claims of discrimination if individuals feel they were treated unfavourably due to a protected characteristic.
With this in mind, it would be a good idea for you outline your approach to staff ahead of time, either by holding a staff meeting or distributing an email that explains their position. It is also worth considering that some individuals may look to circumvent your client’s rules by phoning in sick in order to vote. Whilst you should not jump to unnecessary conclusions in these instances, you will be free to take disciplinary action if you have evidence to show that the illness was fabricated. 
 Reproduced with permission from Croner Taxwise