YORK buses will soon be subject to new emission rules, and drivers will face fines if they leave engines running on stationary vehicles.

The measures were agreed on Thursday night as part of a council push to cut down on harmful pollution and improve air quality in York.

Figures show that while air quality in general has improved across the city since 2010, in some areas the measurements of harmful nitrogen dioxide “persistently exceed” the levels they should be at. The increase can largely be put down to diesel engines - including ageing diesel buses.

The new “Clean Air Zone” (CAZ) means that by 2020 most buses in the city will have to meet emission standards, but campaigners claimed the actions do not go far enough.

Green party activist Ginnie Shaw told the city council’s executive that while her party supported the proposals, they feared York was “falling behind” other cities in its fight on pollution, and were disappointed to see very little progress made since last summer.

She added: “Now that we can confidently anticipate ultra low emission standard Euro 6 for all Park and Ride vehicles by 2019 it’s disappointing to see Clear Air Zone plans for the city slipping back by two years from what was set out in the council’s 2013 strategy.”

The authority should be setting out a timescale for including goods vehicles in the restrictions, as well as longer distance buses which are exempted from the new rules, she added.

“It’s important to be clear there is no safe level of particulates, and we should not be settling to getting nitrogen dioxide down to World Health Organisation annual average maximums.”

However the transport staff behind the plans said it was disingenuous to claim York was falling behind as the city is still the first to introduce a CAZ, and added that the move would make a significant contribution towards improving air quality.

Cllr Andrew Waller, who is in charge of environmental matters at the council, said he was pleased to see the impact of brake and tyre particulates being considered as well as the problems caused by exhaust fumes.

He also pushed for the council to start looking at things it can do with its own fleet of vehicles to help in the air quality fight.

New “anti-idling” measures were also approved to stop drivers leaving their engines running and pumping out exhaust fumes.

They mean that drivers will face £20 fines if they don’t switch off their engines when asked by a council worker.

A report prepared for the executive meeting said enforcement action would only be used “as a last resort”, and would only apply on public highways.