Plans to reform the council tax are "timid and tardy" and could have been implemented sooner to help school children, according to the Scottish Liberal Democrat leader.

Willie Rennie questioned why higher charges for residents in the four highest bands that will bring in an extra £100 million a year for education were not brought in earlier to avoid what he said were cuts of hundreds of millions of pounds imposed in last week's budget.

First Minister Nicola Sturgeon accused Mr Rennie of "making things up as he goes along", highlighting the £80 million of additional investment for attainment in schools announced by Finance Secretary John Swinney last week.

Speaking during First Minister's Questions at Holyrood, Mr Rennie said: "Last week the First Minister cut hundreds of millions of pounds from education budgets.

"She told us she had no choice, her hands were tied, but she would bring these cuts to an end as soon as she had the powers.

"This week she announced extra money for education. She did so without gaining one single additional power at all.

"The cruel twist for children is that they will not see a single penny until next year."

Mr Rennie called on Ms Sturgeon to explain why she had not invested the money earlier.

He added: "Massive cuts for one year could set back a child's chances for a lifetime.

"Scotland used to have one of the best education systems in the world but it has now slipped down the international rankings.

"The situation is urgent. One penny on income tax would generate five times as much for education now than her timid and tardy proposals would next year.

"Even though she had all the powers, she still cut education budgets last week. Surely the First Minister can no longer boast education is her top priority?"

Ms Sturgeon said: "Willie Rennie is now just making things up as he goes along.

"Gross revenue expenditure on education has increased in each of the last three years, council plans show that in this financial year they're spending a further £150 million, last week the Finance Secretary announced the doubling of the attainment fund, yesterday I announced plans that will result in an extra £100 million every year for education."

She added: "I know that the Liberals' position is that having spent the last five years helping the Tories cut our budget they now want to spend the next five years hiking up the taxes of everyone earning over £11,000 a year.

"That is not my position. I will continue to argue for a fair and balanced approach which gets money into education."