The five-person "experts group" will not report until next month, but that did not stop Sir Tim Brighouse from speaking out a joint conference of the NUT and National Association of Head Teachers this week.
Sats were too crude when it came to assessing primary schools, he said. The current assessment was "19th century" and he was "pushing like mad" for more trust in teachers. "If we are going to assess group work, working in a team, being a good communicator and all the things that employers of the future want us to do, you can't do that through formal written exams and that means it has got to be done through people," he said. Boosting teachers as assessors was crucial, adding that "exams were deeply flawed in some cases".
Recommending the end of national tests at 11 would mean the experts' group stepping beyond its remit, but Sir Tim said he intended to "push the boundaries".
He gave qualified backing to the school report card that the Government has suggested as a new way of providing parents with information.
But he said it would be "pointless" unless it prevented league tables and said he opposed the Government's idea of grading schools with a single letter or number.
Ofsted would need to shift if teachers were to have a balanced scorecard, he added.
Other group members are Sir Jim Rose, heading the Government's primary curriculum review, Maurice Smith, a former chief inspector of schools, and headteachers Yasmin Bevan and Gill Mills.