The campaign breaks on 24 July - the same day advance tickets go on sale. The advertising part of the rail company's sixth-month countdown to the launch of HS1.
In May, Eurostar launched a national marketing tour to promote its High Speed 1 service. The five-month tour, which started on 1 May is visiting 50 cities in the UK to showcase the national benefits of the new high-speed service linking the UK with France and Belgium.
Tourism by rail to regions in the north and west of London is expected to increase significantly when the High Speed 1 launches.
Eurostar recently joined forces with six other European high speed train operators to promote the benefits of high speed rail travel and encourage people to travel by train rather than plane between cities in Western Europe.
The alliance, Railteam, aims to offer travellers seamless train travel across the Western European high-speed rail network which links more than 100 major urban destinations in Europe.
The benefits of the alliance and of high speed train travel will form the basis of Eurostar's marketing in the run up to the switch to its new London terminal at St Pancras International in November.
Fallon was appointed as the lead agency on the £10m Eurostar account in March.