Among them are Socialist MEP Silvia Adriana Ticau from Romania and Anni Podimata from Greece, who are the rapporteurs on proposals to revise EU rules on the energy performance of buildings and energy labelling respectively.

Another returning Socialist MEP is Belgian Saïd El Khadraoui, rapporteur on the "Eurovignette" proposals on road charging for heavy vehicles. UK Green Caroline Lucas, who is leading discussions on legal proposals to combat illegal timer, has also been re-elected.

Romanian Liberal MEP Magor Imre Csibi, the parliament's lead negotiator on plans to extend the bloc's ecodesign directive to energy-related products such as taps and construction products, failed to gain re-election. But this will not affect the law's adoption as an agreement with governments was struck in March.

Several MEPs active in the environmental field either stood down or were not re-elected. Irish centre-right member Avril Doyle, who shepherded key proposals to revise the EU emissions trading scheme (ETS) through parliament last year, has retired.

UK centre-right MEP Caroline Jackson was another not to run for re-election. A former chairman of the parliament's environment committee, Ms Jackson was a well-respected voice on EU waste management policy. Last week Ms Jackson told ENDS that the next parliament would have to closely monitor implementation of the revised EU waste framework directive.

A number of newly elected MEPs are expected to take active part in the environmental policy debate during the next parliament. These include the French campaigner turned Green MEP José Bové and his Green compatriot Yannick Jadot, the former head of Greenpeace in France. Corrine Lepage, a former French environment minister, will join the liberal ALDE group.

Negotiations between the parliament's political groups will get under way in the last week of June to decide on the membership and chairs of the various committees. Under recently agreed rules, the overall share of MEPs from each political group in parliament must be reflected in the composition of all committees.

Meanwhile several parliament sources have denied rumours that the current environment committee – which also oversees public health policy – would be split into two separate committees for environment and public health.