MPs who hire their wives and children as staff will be made to prove they are the best candidate available, the new head of the expenses watchdog has indicated.

In her first interview in the job, Ruth Evans, chair of the Independent Parliamentary Standards Authority [IPSA], said the public now expects “equal opportunity employment” in MPs’ offices.

Around 150 MPs – close to one in four – have a family member working in their office, while a number of prominent politicians have faced complaints about their arrangements.

Currently MPs face few limits to hiring partners or children. They are limited to hiring just one at a time and must publicly declare the situation.