In theory, yes it seems that your employer could forbid you from volunteering at a soup kitchen. Though I doubt that is the sort of activity that your employer wishes to prevent. Of greater concern to companies is those activities that conflict with the interests of the company.
Things that your employer would be more likely to object to:
- Employment in a second job
- Ownership(full or partial) of company in excess of the amount allowed(5%)
- Organizations that have been named as Terrorist organizations or restricted or prohibited due to their illegal activities.
- Participation in illegal activities
- Activism in groups like Occupy Wall Street, PETA, Sea Shepherds, et.
- Activism in groups whose mission runs counter to your employers business interests
- Participation in non-government armed groupsa militia
It is unlikely that your company is going to have a problem with your volunteerism though it is possible so I would recommend that you disclose an membership and activities you are involved in. If you are reluctant to do so then you should probably consult a solicitor(Lawyer) about your concerns and liabilities if you choose not to disclose. It is possible that you have rights that are being violated by this clause though a solicitor would be in a better position to judge this.
