A COMPREHENSIVE count of the number of people attending next month's grand prix in Melbourne will not happen, after the Baillieu government blocked it.

Attendance figures for the event have long been contentious, with opponents of the race - who have counted numbers themselves - arguing the official figures are unreliable.

Greens MP Sue Pennicuik moved a motion in State Parliament this week calling for a ''full and accurate count of attendance'' at the event, including a breakdown of paid general admission, grandstand and corporate suites, complimentary and free admission, and the number of free passes issued but not used.

The Australian Grand Prix Corporation's 2012 annual report contained an attendance estimate. ''More than 310,000 people were estimated to have attended this year's event over four days, our largest crowd since 2005, with an estimated 115,000 fans on race day alone,'' it said.

Ms Pennicuik said it was time to get independent and accurate attendance figures for the event.

''Let's once and for all require them to do it,'' she said.

''I go to the cricket … halfway through the cricket they say there are 40,327 people here, halfway through the game, and somehow, the grand prix, even though they have got the captive people in there surrounded by a fence and a gate, don't seem to be able to do that.''

Ms Pennicuik said the crowds at AFL games are also displayed on the scoreboard. ''They can tell you down to the last person how many people are there.''

She said it would not be hard for an accurate attendance count at the grand prix.

''I mean, really, why can't they have some turnstile there?

''What argument do they have for not doing it?''

She said it was basic information that the public had a right to know.

The chief executive of the Australian Grand Prix Corporation, Andrew Westacott, said ''due to the size and temporary nature of the Albert Park circuit, we use a methodology that includes a variety of inputs, including ticket sales, to calculate estimated attendances for each day of the event''.

''The key measure of success of the event is determined by sales revenues, which have increased 14 per cent since 2010.''

Last year's race cost Victorian taxpayers $57 million, and the annual cost of the event is tipped to hit $60 million by 2015.

A spokeswoman for the state government declined to say why it had voted in Parliament against the motion to count those attending the race.

Instead, she said reports the government and Tourism Victoria had commissioned had shown the economic value of the event to Melbourne.

''The government has repeatedly said that the grand prix is good for Melbourne and Victoria, and that there are three more races to be staged here in Melbourne during the terms of the current contract,'' she added.