Anglo-Swiss chemicals firm Ineos is privately leading an industry lobbying attempt to avoid paying for the cost of decarbonising Britain’s economy.

Documents released under freedom of information rules reveal that Ineos is pushing the government to use Brexit as a chance to exempt the chemicals sector entirely from climate policy costs.

Currently, energy users pay a levy to support green energy providers, such as offshore windfarms. Last week, the government announced £100m worth of cuts to the energy bills of heavy users, meaning the chemicals, cement and steel sectors will pay less towards subsidising low-carbon energy generation.

That new help comes on top of exemptions worth £250m already awarded to such energy-intensive industries, but the documents show that Ineos is pushing for even more generous treatment.

Billionaire founder Jim Ratcliffe, who is the chief executive and chairman, promised a British shale gas revolution in 2014 to produce gas for energy and the chemicals it needs for the company’s Grangemouth refinery in Scotland.

Although Ineos’s shale drilling efforts have run behind schedule, the materials show the company has been busy lobbying behind the scenes to remove barriers to fracking and weaken environmental taxes.

The cache of progress updates, letters and meeting notes comes from the Chemistry Growth Partnership, a government-industry initiative. Ineos is a member of the partnership and its director, Tom Crotty, chairs the initiative’s energy work.

One document dated shortly before the European Union referendum said: “Outside the EU: simplify the UK policy mix and seek a single route to 100% exemption from policy costs and CCL [climate change levy, an environmental tax]. Seek a low-cost alternative to EU ETS [the EU’s carbon trading scheme].”

Another policy long in the group’s sights is the UK’s carbon floor price, a carbon tax on electricity generators. The partnership and Ineos want to see it abolished in a bid to cut energy costs passed on to the chemicals sector.

Guy Shrubsole, a campaigner at Friends of the Earth, which obtained the materials, said: “If Ineos got their way, the petrochemicals industry wouldn’t bear any of the costs of cleaning up their carbon pollution.”

The stated goal of Ineos and the partnership’s lobbying is to pave the way for fracking and extracting shale gas. Documents say the objective is to: “Support appropriate policies to enable the safe exploitation of unconventional gas [shale gas], sustainable use of biofuels and optimal use of waste resources.”

To do that, it wants a “level playing field on energy and climate-related policy costs”. In other words, the chemicals sector wants to be exempt from paying for the UK’s various climate policies in the form of business taxes and levies added to energy bills. One document from February, before last week’s £100m giveaway, says the partnership had “lobbied hard” to achieve the exemptions previously awarded by government.

The government said it did not share their views on abolishing the carbon floor price. “The Chemistry Growth Partnership is an industry-led body which sets its own agenda and whose views are independent of government,” a spokesman said.

A spokesman for the Chemistry Growth Partnership said: “As an industry, our opposition to the carbon floor price has been consistent since the day it was announced and predates the CGP by several years.”

A spokesman for Ineos said the company “supports UK manufacturing and has consistently argued for a level playing field on its environmental legislation and competitive energy costs, to enable it to compete in world markets”.

He continued: “Ineos has consistently opposed the carbon floor price, as we have always seen it as a UK-only tax on carbon which makes the UK uncompetitive on energy against the rest of the EU.”

Ineos recently increased its shale gas prospects in the UK by 10% when it bought 15 shale licences from French energy company Engie for an undisclosed sum. It now has rights to explore across 1.2m acres in the East Midlands, Yorkshire and Cheshire.

The company had promised to submit 30 planning applications to drill and explore for shale gas last year. In January it submitted its first application, for Marsh Lane in the east Midlands, but the chief executive of Ineos Shale has promised others are being prepared. “We are a little behind where we’d like to have been,” said Gary Haywood at a recent energy security conference. “You can expect to see a lot more coming through from us.”