Tommy Sheridan said the parties had "earned the right"

Mr Sheridan said the Socialists and the Greens had earned the right to tackle Jack McConnell every Thursday in the Scottish Parliament.

At present only one of the two party leaders is allowed to question the leader, a rule which the procedures committee is due to examine.

Meanwhile, Jack McConnell and SNP leader John Swinney clashed over Scotland's fishing industry.

The Greens and Socialists gained official party status when they won seven and six seats respectively on 1 May.

The committee will look at questions over the summer Presiding Officer George Reid

Mr Sheridan raised the issue in a point of order at the start of the first FMQs since the election.

He said: "There are two new political parties in this parliament, each of which have earned the right to weekly question the first minister on the issues of the day, and that has been denied today to one of those parties."

But Presiding Officer George Reid said the rule would not change until the procedures committee had studied it.

He said: "The committee will look at questions over the summer. I'd hope to have a longer form of questions for the first minister in place by the second week after the recess."

Mr McConnell angered the Greens and Socialists earlier this month when he suggested the two parties could be given the opportunity to question him on alternate weeks.

John Swinney: No laughing matter

Meanwhile, the first minister dismissed SNP claims for parliament to have greater power over the fishing industry.

Mr McConnell said: "It may surprise some members in the chamber, but fish can move from one set of coastal waters to another.

"Fish can travel across the sea and, therefore, we need to have a common fisheries policy in Europe, so we can have a common approach."

Mr Swinney said he was glad the first minister thought the fishing industry was "a laughing matter".