ExxonMobil and BP have thrown their support behind the mammoth Alaska LNG project as environmental groups continue to criticise the scheme, which already is facing an uncertain future, writes Caroline Evans.

In separate letters filed last week with the US Federal Energy Regulatory Commission (Ferc), the supermajors threw their support behind the proposed liquefied natural gas project.

ExxonMobil said the $43 billion plan is in the public interest and could be developed with minimal environmental impact.