The registration number of a rally bus on Sunday indicates that it is more than 15 years old. (Sanjoy Chattopadhyaya)

The Left Front rally on Sunday, touted as a turnaround point by supporters, was powered by illegal wheels.

In a blatant violation of a high court order, the rally organisers deployed old and banned vehicles by the hundreds to ferry crowds to the Maidan and back.

Buses more than 15 years old, banned by the court in the Calcutta Metropolitan Area to rid the air of foul fume, were seen parked on the Maidan and several roads leading to it, bearing Left Front flags.

The tell-tale signs of their age lay in their registration numbers, which started with three letters such as WMH, WGB or WBU — the numbers that were issued till the system was computerised in 1992.

CPM leader and transport minister Ranjit Kundu admitted that a “few old vehicles” did come from the districts but made light of the violation, saying: “It’s not a big deal as these buses came only for a day”.

Leaders of the Bengal Bus Syndicate said the Left Front had hired at least 500 such buses to carry supporters from various districts and back.

“It’s an outright violation of the court order. No vehicle more than 15 years old is allowed to ply within the city from September 1, 2009,” said green activist Subhash Dutta.

The court had passed the ban order on July 18, 2008, on a petition filed by Dutta. A series of appeals followed but the court rejected them and upheld the earlier order on August 28, 2009. The transport lobby had also moved the apex court but failed to get a favourable order.

Why were the buses not booked? “We were asked not to file cases against the banned vehicles fitted with Left Front flags,” said a traffic sergeant posted near the Maidan.

An officer at Lalbazar said he and his colleagues could not be bothered with the ban flout as they were busy with “more important assignments”, such as managing traffic.