The European Parliament could clash with the European Council of Ministers over limiting particulate matter in ambient air - a move that could pressure governments into limiting the use of diesel.

Tougher measures that have already been rejected by EU ministers have been re-tabled by the Parliament’s environment committee.

MEPs are especially focusing on the finest particles, PM2.5, which cause most damage to lungs.

The committee proposes setting a non-binding guideline limit of 20µg/m3 from 2010 - tighter than the compulsory limit favoured by the council of 25µg/m3.

Furthermore, the committee wants its 20µg/m3 limit made compulsory from 2015. MEPs have proposed reducing maximum concentration levels of the largest particles - PM10 - to 33µg/m3 on average per year from 2010, while EU ministers want the limit at 40µg/m3.

The committee is also proposing some flexibility – a three-year exemption from the PM10 rules for “areas or cities which cannot meet the targets because of site-specific dispersion characteristics, adverse climatic conditions or trans-boundary contributions".

The full Parliament is expected to back these proposals.