The answer is No, due to three major reasons:
- Citizenship: Those who are supposed to "separate" don't have right to do that as they are not citizens of Ukraine;
- Legal issues: The Constitution of Ukraine requires such actions to be asked on a national referendum. Geo-political orientation of vast majority of citizens of Ukraine is for unitary country, partnering with and/or taking membership in EU;
- Territory: Referendum votes on territories that Russia has occupied and where the separatist movement is most powerful (2.2% of territory) — are not sufficient;
Who are supposed to "separate"
You can't be a "separatist" when you don't even have citizenship of the country you're trying to "separate" from.
The top commandment of those "rebels" and "separatists" are holding Russian passports, and vast majority of them are acting officers of Russian army.
- Igor Bezler, Lt.Col. of General Staff of russian intelligence, a citizen of Russia, a leader of Luhans'k "People Republic";
- Igor Girkin, Col. of General Staff of russian intelligence, a citizen of Russia, a leader of Donets'k "People Republic";
- Alexander Borodai,
Major-General (* by 2002), a citizen of (guess what) Russia, "Prime-Minister" of Donets'k "People Republic". This article (in Russian) says that in 2002 he was assigned Deputy Director of Information Policy and "Special Projects" of KGB.
Let me repeat, a Deputy Director in KGB;
(Note: Pravda.ru is the official mainstream newspaper, controlled by Russian gov't.)
As it becomes clear, these people are not just farmers who decided to join "rebel" movement. They are acting officers of russian military and/or KGB, holding top positions and specialized in "arranging delicate operations" (see the linked article).
"Separation" for them is simply taking return ticket to Russia. Hopefully, they have time to do it before they get neutralized in a battle.
According to the Constitution of Ukraine, questions about territorial integrity can be changed only with nationwide referendum. Simply speaking, you can't declare your house an independent state unless 50%+1 Ukrainian citizens let you do that.
The actual geo-political orientation of citizens of Ukraine
(image courtesy of Washington Post)
Many of people who really wanted to separate, actually wanted back in USSR, not "back to Russia". After occupation of Crimea they realized the whole picture, and the number of those who want "back in USSR" may have reduced dramatically.
Currently occupied territory
Phrases "mostly in West" and "mostly in East" look biased because they make a reader think that Ukrainian citizens are split nearly 50/50 regarding this question. The truth is opposite.
This picture says: "Novorossiya" ** as a russian sees it (left) and as it really is (right).
(**) "Novorossiya" is an artificial term Putin has invented during one of his recent interviews, calling such areas occupied by Russian army or supposed to be occupied.
This map shows the front line of Russian-Ukrainian war as of noon, July/20. It is evident that Russian army holds about 25% of Donetsk Oblast' and about 25% of Luhansk Oblast'. In total it is about 13,000 sq.km, which stands for
13 / 603 ~ 2.2% of the territory of Ukraine.
just a note, the border between the two Oblast's is roughly the line where MH-17 crash site is depicted
Summary. It is not about "separation". It is Russian war against Ukraine, a covert operation ran by regular russian army that is intended to look like rebels are attempting to "separate" from Ukraine. There's simply no electorate wanting to Russia, and my personal feeling that since March 2014 (see the Washington Post info-graphics) that number has been reduced two- or three-fold.