Former Polish Europe Minister and Chair of the Foreign Affairs Committee of the European Parliament Jacek Saryusz-Wolski thinks that European policymakers should demand that Ukraine finally choose between the East and the West.

"European policymakers should demand that Ukraine finally picks one side of the fence," the MEP wrote in his blog on the Web site of the Financial Times.

Saryusz-Wolski wrote that Kyiv is sitting on the fence and using two-sided tactics in its relations with East and West.

"Ukraine must get off the fence when it comes to its relations with Russia and the European Union," reads the posting.

According to Saryusz-Wolski, "hopes that an EU-Ukraine association agreement, including a deep and comprehensive trade agreement, might be signed at the November Eastern Partnership summit in Vilnius are fading."

The MEP said that Ukraine's negotiations to become an observer in the Customs Union of Russia, Kazakhstan and Belarus have just been concluded.

"Are these two-sided tactics by Ukraine aimed to get the best possible deal from Brussels?" reads his posting.

At the same time, he said he assumed that there is "a genuine option of Ukraine choosing the East over the West and forsaking its European perspective, to the detriment of its own interests and those of the EU."

Saryusz-Wolski also noted that Russia is "notorious for exerting pressure on Ukraine through its energy policy."

"It is pressing for the creation of a gas consortium in Ukraine, in which Gazprom would hold a decisive stake, thus taking control over Ukrainian gas infrastructure and excluding any EU presence," he wrote.

The politician added that should this scenario materialize, it would run counter to the EU's rules, as well as be detrimental to the interests of Ukrainians, some 60% of whom oppose giving up control over their gas transmission system to Russia.

The politician also commented on the economic impact of either the Customs Union with Russia or with the EU. He mentioned that, according to experts, a Russian deal would actually cumulatively decrease Ukrainians' welfare by 0.5-3.7% GDP, while an association and deep trade agreement with the EU would cumulatively increase Ukraine's GDP by as much as 11.8% in the long-term.

"A free trade agreement with the EU, rather than with Ukraine's eastern neighbors, would aid the modernization of the country's economy, facilitating technology and business innovation. A free trade area between the EU and Ukraine can also bring benefits that go far beyond regular trade relations, with improved cross-border infrastructure and the strengthening of Ukraine's institutions," reads the posting.

"Our Ukrainian partners would be wise not to overplay their game. European business people, who understand the benefits of market integration with Ukraine and who know the obstacles they face in Ukraine, should encourage Kyiv to make the right decision. They should remember the possible negative impact of any Ukrainian trade pact with the Customs Union of Russia and its partners," the MEP said.