A letter describing Vince Cable as the "contact minister for Shell" has raised fresh questions about the business secretary's relationship with the oil giant.
In the letter to Cable dated 19 March 2012, Malcolm Brinded, the then chief executive of Shell Upstream International, sets out how the company would like the coalition to harden its line against the European Fuel Quality Directive, a policy initiative aimed at reducing emissions from transport fuels.
In the past the UK government has abstained or remained neutral, but Brinded lobbies Cable in the letter, released under the Freedom of Information Act to the research group Corporate Watch and seen by The Huffington Post UK, to vote against the FQD and to encourage other European Union states to do the same.
He tells Cable of the need for "a shift in the current UK position of neutrality/abstention to a clear vote against".
Brinded adds: "We judge it particularly important that a change in position is reached and communicated to other member states well ahead of time to maximize the chances of encouraging others in the same direction."
The Brinded letter is also heavily redacted and it is not clear what has been obscured.
Any suggestion that the Lib Dem minister may change government policy on the request of Shell would anger environmental campaigners, who are already suspicious of the coalition's claim that it wants to be the "greenest government ever".
A spokesperson for the Department for Business, Innovation and Skills said the government was committed to a "whole-government approach to developing strategic relationships with major exporters and investors.
"This is a key part of the growth agenda and part of a wider drive by government to improve relationships with companies of all sizes and sectors.
"By understanding business concerns and by being clear about government’s own priorities, the approach will make a real difference to trade and investment."
The spokesperson also said the government would "obviously consider very carefully any possible impact on both the environment and the motorist" before taking decisions related to the FQD and closely related Renewable Energy Directive .
However Brinded's pleasure at Cable being the "minister for Shell" could be embarrassing for the business secretary, as he served as the company's chief economist from 1995 to 1997.
In a statement released to The Huffington Post UK, Corporate Watch highlights the fact that during that particular period the company is alleged to have funded and supported the Nigerian military as it committed international crimes and human-rights abuses and questions how Cable could not have been aware of these activities.
"In 1995 the writer Ken Saro-Wiwa and eight other leaders of the southern Nigerian Ogoni ethnic group were executed by the Sani Abacha military government. This was after a wave of state-sponsored violence in the south of the country.
"In 2011, relatives of the assassinated Ogoni 9, as they became known, began legal proceedings against Shell, accusing the company of collaborating in the murders. Shell agreed an out-of-court settlement in which they paid the victims' families $15.5m, rather then face a New York Federal court.
It adds: "It beggars belief that senior Shell officials, including Cable as chief economist, would not have been aware of Nigerian military activities in the Niger Delta."
Shell has always denied its role in the violence and has said in the past that it "had no part in the violence that took place".
And Cable has also previously insisted he was not involved in or had any knowledge of the alleged incidents in Nigeria.
The access given to Shell by the government has come under close scrutiny in recent months. In August The Guardian revealed that senior officials from 10 government departments attended exclusive "training courses" laid on by Shell.
The report angered environmental campaigners who raised concerns about the access afforded to Shell by senior civil servants.
Jim Footner, head of Greenpeace's climate and energy campaign, told The Guardian it showed that "one of the world's most environmentally damaging companies has shocking levels of access".
"Shell has effectively locked themselves in a room for days with powerful civil servants to promote their own agenda. Our government officials should not be allowed to take part in a two-day schmooze-athon with this company."