How many members have second sources of income ?
IPSA does not hold the information that you request.
The Independent Parliamentary Standards Authority (IPSA) is the body created by Parliament under the Parliamentary Standards Act 2009 to independently oversee and regulate MPs’ expenses. IPSA has two main roles: regulating the business costs and expenses system and administering and paying MPs’ expenses, pay and pensions.
As such, we do not hold information of the private affairs of Members of Parliament.
However, for ease, some of the information you request may be available in the Register of Members’ Financial Interests, which is separately administered by the House of Commons. You can view copies of the Register via this link: http://www.publications.parliament.uk/pa/cm/cmregmem.htm