The Financial Times (p8) reports that his disclosure came with a warning that increased local representation on health authorities and trusts must not come at the expense of their efficient management.
His annual report shows that over the past year the government has appointed five times as many Labour activists to public bodies as Tory ones.
The increase is accounted for largely by more councillors being appointed to NHS bodies as the government pursues its policy of increasing local representation on health authorities and trusts.
Sir Len warned that the trend 'raises a concern that the emphasis on representation may lead to the bodies in question losing the wider management and professional skills and competencies which those holding office need to fulfil.'
Representation 'should not be allowed to swamp the skills and competencies required to be effective' he added.
But Sir Len said his investigation of complaints showed that in the first year of Labour appointments, there was no evidence of political bias in the way they had been made.