By Oana Lungescu
BBC European Affairs correspondent
The European Commission has said Poland may reconsider its veto on the start of talks on a new partnership agreement between the EU and Russia.
Prime Minister Kaczynski is not giving in, but the mood is improving
But the Polish PM said he would only back down if Russia lifted a ban on Polish meat and other farm goods.
Warsaw blocked talks on the pact with Moscow last year, in an unprecedented move that clouded an EU-Russia summit.
But renewed efforts are being made to break the deadlock before the next EU-Russia summit.
The stakes could not be higher: a wide-ranging partnership and co-operation agreement, which would put relations between the 27 members of the EU and Russia on a new basis.
Polish Prime Minister Jaroslaw Kaczynski has now made clear the veto would be lifted, but only if Moscow lifted the meat ban.
Germany, which holds the EU presidency, welcomed this as an important first step.
The President of the European Commission, Jose Manuel Barroso, also described the latest developments as positive, but said it was too early to say whether negotiations could start and when.
The Commission has repeated a call for Moscow to lift the ban promptly, after both EU and Russian experts inspected Polish meat processing plants earlier this year.
A Polish diplomat said his country did not want to block anything, but needed more guarantees that Russia would finally end the ban.