Scotland's largest teaching union has said there is no clear rationale behind planned changes to the way schools are funded.

The Educational Institute of Scotland (EIS) said the Scottish Government has failed to make a convincing case for changing the current funding structures.

The union said ministers had not demonstrated how the proposed changes would improve attainment or equity in schools.

The government is currently consulting on the proposals, which sit alongside reforms of school governance that will see headteachers given a raft of new powers.

The consultation paper sets out two possible future approaches, the first of which would give funds directly to head teachers through a head teachers charter and the second would increase the targeting of funding, along the lines of the approach taken to pupil equity funding.

In its submission to the consultation, the EIS said it did not believe either approach "would drive an improvement in pupil attainment or equity".

General secretary Larry Flanagan said: "While the EIS is supportive of some aspects of the Scottish Government's proposals, such as the potential for regional collaboratives to enhance the support available to schools, we do not believe that wider structural change or a new funding model are essential components in delivering the cultural change which is required.

"We do believe, however, that the level of resource provided to schools is critical in any initiative that aims to raise attainment and improve equity within the education system and we are calling for greater investment in teachers and schools."

Ross Greer MSP, the Scottish Greens' education spokesman, said: "The EIS is right to question whether governance changes will improve educational outcomes for children.

"There is, after all, no compelling evidence that this would be the case. The challenges in Scottish education are far more a result of ten years of budget cuts than they are governance issues.

"When over 4000 teachers, 500 additional support needs teachers and a third of school librarians have been cut in that time, the problem is clearly one of finances but the SNP simply will not admit that."

A Scottish Government spokesman said a response to the consultation would be published in due course.