Ukraine's parliament is something halfway between a wrestling pit and a shady backroom for hatching deals. Optimists believe Sunday's elections will change all that.

Voting in a fresh batch of deputies, they hope, could kick-start a nation hobbled by endemic corruption and reliant on creaking Soviet-built industry.

A simmering separatist war in the east, however, gives many others little faith in a fresh start. The pessimists argue that the conflict and the threat of Russian aggression have drawn attention away from a much-needed reform agenda.

"Politics seems to be too much in the rather business-as-usual mode, so the hope of rebooting the political system with these elections may be disappointed," said regional expert Andrew Wilson, author of "Ukraine Crisis: What it Means for the West."

The Verkhovna Rada, as Ukraine's single-chamber parliament is known, is a rowdy place at the best of times — a perfect metaphor for a dysfunctional political scene. Debates more often than not descend into shouting matches and sometimes all-out brawls. With the country on the verge of an economic meltdown caused by the war and depleted cash reserves, some reinvention is in order.

This weekend's ballot is the culmination of a process sparked by February's ouster of President Viktor Yanukovych in a frenzy of public revolt that turned bloody when snipers began mowing down protesters near Kiev's iconic Maidan square. The collective disgust at the violence and the scale of the disgraced leader's venality, which became apparent as Ukrainians discovered his comically pharaonic private residence, fostered a mood of national unity.

President Petro Poroshenko, easily elected to office in May, has harnessed that spirit to the benefit of his eponymous Poroshenko Bloc. Despite the wide field of contenders, some pundits and polls believe the party may garner enough seats in the 450-member legislature to form a government unaided.

Most of Poroshenko Bloc's rivals share a strongly pro-Western bent. The affection that most Ukrainians once felt for Russia has been soured by Moscow's annexation of Crimea in March. Attitudes have turned poisonous since the outbreak of an armed separatist insurgency in coal-rich eastern regions that Ukraine and the West say is largely the fruit of Russian meddling.

Yulia Tymoshenko, whose magnetic charisma and trademark blond braids made her the emblem of the 2004 Orange Revolution, has become an ardent champion of NATO membership and her Fatherland party has reasonable prospects.

Belying his tame appearance, Arseniy Yatsenyuk — the bespectacled prime minister and Popular Front party leader — has become the poster boy for tough but necessary economic reforms.

The loudest candidate on the political field is pitchfork-wielding Radical Party frontman Oleh Lyashko, whose brand of brash nationalist populism and lavish campaign spending could lift his group into second place.

Campaign advertising has been skimpy on the issues and focused heavily on boilerplate appeals to patriotism and national renewal.

Political consultant Oleksandr Kopil said there are two impulses motivating voters as they head to the polls.

"The first is for stability and a certain dose of security, so that things at least don't become worse," Kopil said. "The second demand, which may have less of a following, is for a continuation of the revolution — stark reforms and changes."

Overshadowing the elections is the pro-Russian separatist insurgency in the east.

The fighting, which has claimed more than 3,000 lives at a conservative estimate, has died down since its peak in the summer. However, the rebels are consolidating and more conflict remains a distinct possibility without a clear settlement.

Territorial sovereignty for Ukraine is a mantra across the political spectrum and the incoming parliament is unlikely to favor compromise with foes the government has dubbed "terrorists." In areas under separatist control, elections will not take place; voting is also at risk in towns along government-held side of the front line.

Popular sentiment is hovering uneasily between eagerness to push back the separatist front and fatigue at the death and destruction caused by the conflict.

Appetite for anti-corruption campaigns is less controversial. In a transparent gambit to win votes, Poroshenko successfully leaned on the outgoing parliament to approve legislation to fire state officials with links to the Yanukovych era.

Voters will expect more of the same from the new parliament, although experts warn there are risks to wide-scale purges like those initiated by Poroshenko.

"The imminent dismissal of civil servants in such numbers raises troubling questions about how effectively Ukraine's badly troubled state institutions will be able to cope with their responsibilities while short-handed," Yuliya Bila and Isaac Webb wrote in a recent analysis for the Carnegie Endowment for International Peace.

The International Monetary Fund, which approved $17 billion in loans for Ukraine in April, says the country has made a promising start, but it worries that conflict in the east and mounting debt for Russian natural gas have hindered progress.

More unpopular measures will fall to the next government to complete. Lightening Ukraine's economic burden will in crude terms mean heating and electricity bills going up and social assistance payments being frozen.

"The new government will be doomed, even more than the outgoing one, to have to effect radical reforms, so not every member of parliament that is elected will necessarily want a position in government," Kopil said.

Russia is the elephant in the room that few candidates seem willing to acknowledge. The Kremlin had an amicable relationship with Yanukovych and has been openly hostile to the leadership that pushed him out of power.

Moscow can still punish Ukraine with a combination of trade embargoes, gas delivery freezes and under-the-table political shenanigans carried out by local proxies.

"Russia politically can destroy the best hopes of any Ukrainian government for reform," Wilson said. "That's the big factor hanging over all of this."