Willie Rennie has given a "guarantee" that education funding will rise under a Liberal Democrat Scottish government - but he has ruled out ring-fencing, which means he cannot ensure councils will spend the uplift on education.

The Liberal Democrats want to put 1p on income tax to deliver £2.5 billion of investment for nurseries and colleges in the next parliament.

The funding would include £475 million for a "pupil premium" worth £1,400 for primary pupils who require extra support and £900 for secondary pupils from disadvantaged backgrounds.

Mr Rennie said the pupil premium "would be part of the council spending programme and it would include the part of the £2.5 billion over the five years".

Asked if he would guarantee a real-terms increase in education funding on BBC Radio Scotland's Good Morning Scotland programme, Mr Rennie said: "Yes we would."

However, he would not guarantee that local authorities would ring-fence the cash.

He said: "Since half of what councils do is education I think it would be one of their top priorities to invest it in schools."

Councils would not be obliged to spend the money on education without ring-fenced protection.

Mr Rennie added: "We want to trust local authorities to be able to invest in areas within their communities.

"I believe that, especially with Liberal Democrats in charge of local authorities, that that investment will go directly to schools."

Mr Rennie said councils "would see the sense" of using the money to invest in education.