Advertising space is to be sold to private companies on the Northamptonshire County Council website, the authority has confirmed.
The council said the money raised would be reinvested into its website and will generate up to £50,000 a year.
It is similar to schemes that other English councils have entered into. Adverts have to meet a criteria of acceptability, with a ban on anything that is inappropriate to children, tobacco, alcohol, pornography and adult content, betting services, political organisations and lobby groups.
But some politicians have criticised a neutral taxpayer-funded body selling its patronage and implied seal of approval to companies.
Former Northampton MP Tony Clarke said: “I’m not against councils making some money from private companies but this is different.
“As a local authority, you have to safeguard your integrity and they have overstepped the mark here.”
A Northamptonshire County Council spokesman said: “This is an initial six-month trial, after which we will decide whether or not to continue.”