All smiles: Labour's Cathy Jamieson and Tavish Scott, Lib Dem

Labour and Liberal Democrat MSPs have given their backing to a coalition deal to run Scotland for the next four years.

The party leaders reached an agreement - which includes commitment to a key Lib Dem goal of voting reform for council elections and Labour's desire for a hard line on youth crime - at about 0100 BST on Wednesday.

Labour's 50 MSPs gave the deal their support after a 90-minute meeting later in the morning.

The deal then cleared the final hurdle of approval by a special committee of Lib Dem members, who met on Wednesday evening.

Leader Jack McConnell said: "I am very pleased to be able to report that the group of Labour MSPs in the parliament has supported the partnership agreement that was struck last night."

He said his party's plans to get tough on youth crime would be implemented in full by the new Scottish Executive.

Lib Dem leader Jim Wallace had branded proposals to jail the parents of unruly youngsters "unworkable" during the election campaign.

According to the partnership agreement, the sentence for breaking a parental order would either be a fine or a community-based punishment.

Even if the parent fails to pay the fine, they would not be sent to jail in the first instance.

Mr McConnell said the executive's "first actions" would be to introduce an anti-social behaviour bill and legislation to reform the health service.

"We have a comprehensive package that will contain every element of legislation, discussions and budgets that are required to make sure that at local level our councils, our police forces and other authorities have the right powers to tackle anti-social behaviour and youth crime," he said.

There was overwhelming support for an agreement which we believe is good for Scotland Jim Wallace Scottish Lib Dem leader

Lib Dem leader Jim Wallace said his party's 17 MSPs had also given the plans their "unanimous endorsement".

"There was overwhelming support for an agreement which we believe is good for Scotland, will deliver stable government for the next four years, and our key policy areas," he said after the two-and-a-half hour meeting with MSPs.

Mr Wallace added: "There was a very constructive engagement between the two parties and I certainly believe it's a win-win for both the parties."

Asked whether there would be PR voting for councils by 2007 he said: "Yes, unequivocally."

He said there was also a commitment to free eye and dental checks and a maximum class size of 25 at primary one level.

Ministerial seats

And the agreement includes the Lib Dem pledge to abolish the Skye Bridge tolls - although he said the terms for buying back the bridge would have to be right.

The Lib Dems are expected to take a quarter of the ministerial seats in the new executive.

The parties are expected to put Mr McConnell forward for election as first minister in the Scottish Parliament on Thursday.

He would then have an audience with the Queen and be sworn into office by judges at the Court of Session before the new Scottish Executive could get down to business.