David Cameron tells us this morning that an incoming Conservative Government will set up a fair pay review to investigate pay inequality in the public sector.

He will ask the review “to consider how to introduce a pay multiple so that no public sector worker can earn more than 20 times more than the lowest paid person in their organisation”.

Fair enough, Dave. But what about the private sector?

Martin Kettle in today’s Guardian tells us that Stuart Rose, the outgoing Chief Executive of M&S, thinks £15m a year is about right for his successor, Marc Bolland of Morrisons, who gets his feet under the desk on 4 May. I wonder what the multiple there is?

The Public Administration Select Committee called for the setting up of a Top Pay Commission in its December 2009 report on “Top Pay in the Public Sector”.

During one of the evidence sessions I asked (a slightly startled) Polly Toynbee how much she earned. £106,000 a year, she said. Good on her.

Her refreshingly direct response to my straightforward question prompted me to table this Early Day Motion on 5 May 2009, which bears re-reading.

POLLY TOYNBEE'S SALARY

Prentice, Gordon

That this House applauds Polly Toynbee, the Guardian journalist and co-author of the book Unjust Rewards for volunteering details of her salary to the Public Administration Select Committee in its first evidence session on Executive Pay in the Public Sector; notes that she receives £106,000 per annum; and urges journalists, broadcasters, commentators, politicians and others to follow her example before pronouncing on pay levels in the public sector by first disclosing their own income, earned and unearned.

Here is the exchange on 30 April 2009:

Q13  Mr Prentice: Most of us here earn about £64,000 a year. Do you feel able individually to tell us what you earn? I ask that question, Polly, because you said why just the public sector, why not the private sector. Should not our tax returns, everyone's tax returns, be put to the public domain? It happens in Sweden. People running for elective office in the United States disclose that information.

Ms Toynbee: I think it is a very good idea. I mean, it would be a huge culture shock at first.

Q14  Mr Prentice: It would.

Ms Toynbee: It would be like nudism, everybody taking their clothes off, but if everybody did it at once, the shock would last a year or two.

Q15  Mr Prentice: Just do not go there.

Ms Toynbee: I think it would be a very good idea. I do not mind saying what I earn, but I think it is a taboo that is quite dangerous at the moment. If you want to know what I earned: I just received my end of year thing from The Guardian and it said I earned £106,000.