The chair of the non-political Hampshire Primary Heads Conference wants an end to tests for 11-year-olds which, he says, distort the curriculum.
And he has called for the other 300 primary and junior schools in the county to join him in putting together an alternative system, based on teacher assessment and testing individual children when they are ready.
Mr Porch, head of Sun Hill junior, Alresford, said: "I am mindful of the legal hurdles, but in the meantime I want heads to lay down their cards and say we have no intention of doing formal Sats in 2005.
"Sats have had their time. I want Hampshire to provide a thorough, rigorous profile of a child from key stage 1 to KS3. And Sats are not useful for that process."
He is consulting with heads in the authority, which came 34th out of 150 English councils in the performance tables last year.
"We don't want to be revolutionary. We want the Government to look at us as a pilot authority for a Sat-less society. It hinted in the primary strategy document that it will pilot assessments for KS1.
"We want to be more radical and we are offering it hundreds of schools ready to do pilot assessments at KS2."