Eurostar has pulled a wide-ranging account out of Consolidated Communications and is looking to bring in an agency with greater public affairs firepower.
A handful of lobbying firms are currently fighting it out for the extensive brief, which covers both public affairs and corporate PR.
The new agency will aim to communicate Eurostar's green credentials and help the service to prepare for potentially problematic EU legislation.
Eurostar director of communications Simon Montague is presiding over the pitch alongside chief executive Richard Brown. The pitch is in the final stages and an appointment is expected this month.
Consolidated was brought in by Eurostar in late 2005 for a brief spanning public affairs, corporate and consumer PR.
The agency oversaw Eurostar's move from London Waterloo to the new St Pancras International station.
'It did a very good job during the busiest years of Eurostar's history,' said Montague, a former Fishburn Hedges consultant.
But he added that new public affairs support was needed for Eurostar 'to face some of the challenges ahead'.
Eurostar is committed to reducing carbon dioxide emissions by 25 per cent per passenger journey by 2012 and is keen to communicate this policy to both passengers and decision-makers in Westminster and Whitehall.
Eurostar is also preparing for EU legislation that will open up competition for the railways.
The 'open access' legislation is due to come into effect in 2010 and means that Eurostar could potentially come under threat from a new rival.
One possible such rival is Air France KLM, which last week confirmed it was considering offering high-speed rail travel across Europe.
The Franco-Dutch airline, the world's biggest airline by revenues, is discussing a high-speed rail alliance with a French firm, Veolia.
'As part of the opening to competition of rail transport in 2010, Air France and Veolia are looking into the possibility of a partnership to create a new high-speed rail player on the European scene,' said an Air France-KLM spokesman.
Eurostar has a 14-strong communications operation, including senior public affairs officer Seth Williams.