The Prime Minister and his wife, Cherie, met Sir Cliff after the Blairs attended one of his concerts at the Royal Albert Hall in London. Mrs Blair is understood to be a long-term fan.
Sir Cliff said he had told Mr Blair the millennium festivities should emphasise the Christian nature and include more charitable giving.
"We talked about the spiritual aspect," Sir Cliff told The Independent, "and they were right behind what I was saying. They were very much in favour of making a spiritual statement.
"The Prime Minister is marginally disappointed they can't do something spiritual at the Dome. But he did say he was very much in favour of my making a Christian statement. Let's face it, it's very much easier for someone like myself to make a Christian statement."
The result of the meeting became evident yesterday when the singer announced he would be playing a millennium eve concert in Birmingham, with all the proceeds going to charity.
He said he was not against stars being paid for performing on the night as long as they donated the money to charity.