One rule for them, another for us: the row over MPs expenses has highlighted big differences in the tax rules governing Parliament and ordinary taxpayers.

While you and I would have to pay income tax on expenses from a second home, MPs are not charged. They also pay no income tax on family travel. Accountants calculate that MPs avoid an average of more than £54,000 a year in tax on their parliamentary expense claims which, according to official figures, usually exceed £135,000 each.

However, don’t forget it’s quite legitimate to nominate a second home as your main residence if you have lived there to benefit from a capital-gains tax exemption.

We look at what HMRC will allow:

What are the rules on expenses?

Employees are entitled to claim tax relief for business expenses either paid by their employer or paid personally and reimbursed, as long as the costs are “wholly, exclusively and necessarily incurred” in the course of their jobs.

The scope of this tends to be limited: commuting from home to the office does not meet the test, nor does heating and lighting for a home office, unless you are self-employed. Professional subscriptions paid by employees or deductions for business mileage do qualify, though.

Could I claim my second home as my main?

Yes, but only for capital-gains tax purposes, not for income tax as MPs can. Your “principal private residence” is exempt from tax on gains. You can choose which property to exempt and it is possible to switch to another after only a week. Both homes must be fully furnished, but you do not need to prove that you spend more time in one property than the other.

To get the exemption, write to the taxman stating which property you wish to nominate for tax relief.