Massive upgrades would be needed throughout the 1,830km line from Germany, through Poland and Belarus to Russia.
The upgrade would link the two capitals with a 160km/h connection by 2014.ZThe short German stretch between Berlin and the Polish border is already able to cope with the higher speeds and Russian rail company RZD plans to upgrade the line from Moscow through Russia and Belarus to Poland.
But an RZD spokesman said it would only do so if Polish state rail firm PKP commits to upgrading its line to the German border before the 2014 Winter Olympics, in the Russian resort of Sochi.
RZD has already begun constructing a high speed line from Moscow to St Petersburg and plans to build a line from Moscow to Sochi.
Using European Union funds and PKP's own investment, upgrade of the Polish stretch has started as part of an overall upgrade of the country's rail system, but this will only amount to £6.3M in 2008.