A majority of voters think Education Minister Hekia Parata's poor performance should have seen her dumped from the Cabinet last month, according to a TVNZ/Colmar Brunton poll.

Ms Parata will tomorrow announce the Government's final decisions over the future of 31 Christchurch schools, with the prospect of a number of closures fuelling disapproval of her handling of the education portfolio.

Fifty-nine per cent of voters polled by Colmar Brunton believed Prime Minister John Key made the wrong decision by keeping Ms Parata as Education Minister in last month's Cabinet reshuffle following a torrid time during which she oversaw the class size backdown, the Novopay debacle and the breakdown in communications with Education Secretary Lesley Longstone and her subsequent departure.

But the poll also had good news for National, with a 5 percentage point jump in support taking them to 49 per cent. Prime Minister John Key also gained five points, according to the preferred prime minister measure, giving him 44 per cent. Labour was on 33 per cent and the Greens 11 per cent.