The Attack on Sleaze: Firm's key role in pounds 1bn station decision: Lobbyists may have tipped balance for cement company, writes Will Bennett

Decision Makers is one of the most experienced lobbying firms operating at Westminster and is believed to have played a crucial role in the battle for the site of an international station on the Channel tunnel rail link.

The company is headed by the formidable Maureen Tomison, who won the title of European Woman of Achievement last year. Its headquarters are in Gladstone Street, near Waterloo Station, just a few minutes' walk from the Houses of Parliament.

The firm also has offices in Brussels, Budapest, Glasgow, Moscow and Prague, to handle accounts in aviation, defence, the environment, telecommunications, pharmaceuticals and several other fields. It boasts that it 'brings together a unique blend of expertise and contacts in both Houses of Parliament, all political parties, EC institutions, the media, the City and industry'.

As well as Dame Angela Rumbold, who resigned as an executive director yesterday, its management team includes Lord Mulley, the Labour peer and former Secretary of State for Defence. Allan Stewart, Conservative MP for Eastwood, is a former director of its Scottish subsidiary.

A number of former British, EU and eastern European civil servants are on its staff. This kind of experience played a critical role in winning the site of the Channel tunnel rail link international station for Ebbsfleet, near Gravesend, Kent. The Ebbsfleet project, backed by the cement manufacturers Blue Circle, came from nowhere to beat rival bids from other sites in the London region. Apparently operating within the rules, the Ebbsfleet campaign achieved more high-level access than one of its principal rivals, the east London borough of Newham, which wanted the station at Stratford.

The decision, announced last month by Brian Mawhinney, the Secretary of State for Transport, is worth about pounds 1bn and will lead to the building of 40,000 homes as well as the station. The stakes played for in Westminster today are high.