MPS have rightly faced a public backlash over their outrageous expense claims. Now, it seems, their wives and husbands are also in the firing line.

As we report today, MPs will be forced to sack family members working in their Commons offices, possibly as early as next year.

The practice has been discredited after Derek Conway, the former Tory MP, had to pay back thousands he paid to his two sons after an inquiry found no evidence that they actually did any serious work for him.

The measures are due to be unveiled next month – aptly on the eve of Guy Fawkes’ night – as part of Sir Christopher Kelly’s ongoing investigation into the expenses scandal.

MPs, already furious at Sir Thomas Legg’s demands to repay some claims previously approved by Commons authorities, are unlikely to embrace the recommendations with magnanimity.

Nor are their spouses.

Some have already taken legal advice, asking if the rule change breaches employment law.

Others are planning some kind of job swap in a bid to beat the ban.

We believe that the Parliamentary expenses system is so badly discredited that only a clean slate can restore public confidence in our Parliamentarians.

But should that clean slate extend to family members who may have given up promising careers? How can it be fair that a wife or husband gets handed their P45, but a lover can stay on because they are not married?

Sir Christopher must be careful that his review does not become a witch hunt.