Polish commissioner to take on Libertas in campaign

Ms Hubner said she considered the June elections of particular importance, because it would be the first time they would be about Europe, not just national issues.

"This is because of the treaty and the new political group - Libertas - which will raise issues to which we will have to react strongly. These elections will be indeed European in nature, it will be challenging and I would like to say what I have to say about Europe during this campaign," she explained.

The Polish commissioner stressed the need, especially in turbulent times, to "talk loudly about the common European interests," which need to be protected.

The Libertas party set up a branch in Poland at the beginning of this month. Its leader Daclan Ganley, who supported the No-campaign leading to the rejection of the treaty by Irish voters last year, says he is not opposed to the European Union but to the proposed Lisbon Treaty which he argues will limit member states' national sovereignty.

Polish president Lech Kaczynski has declined to sign the treaty until it is accepted by Ireland.

Shift in political affiliation

Ms Hubner's move also marks a shift in political families. Currently, the Polish commissioner is listed on the European Socialists website, but the prime minister's liberal Civic Platform Party she would run for is affiliated with the centre-right European People's Party (EPP). The EPP currently holds the majority in the EU parliament and is expected to keep it after the elections.

Ms Hubner denied being a socialist, explaining that her affiliation came about in 2004 because there was a Social-Democratic government in power in Poland, which sent her to Brussels as a commissioner.

"It's true that when I was appointed commissioner it was a Social-Democratic government, so many people associate me with them. But if I look for any political conviction, I would probably call myself a liberal democrat - that is more or less what I am, " she said.

The 60-year old politician stressed that in the 1990s she cooperated with all governments, irrespective of their colour, first as an advisor and then as an EU affairs minister responsible for Poland's EU accession.

Hubner replacement?

Asked if she would accept a second mandate as a commissioner if the Tusk government nominated her for the new college, Ms Hubner said that it was too early to think about it, as her current focus was on the EU elections.

She said she had not yet considered anyone to temporarily replace her during the May and June election campaign.

One scenario circulated in Brussels is that during her leave of absence, the regional policy portfolio might be taken over by Czech commissioner Vladimir Spidla, who currently oversees employment and social affairs.