MOSCOW - The five candidates in Russia's presidential election continued to drum up support before the nation's voters go to the polls on Sunday, while the likely winner, Vladimir Putin, took the opposition to task for "lacking constructive proposals".

Communist leader Gennady Zyuganov, the Liberal Democratic Party's Vladimir Zhirinovsky, A Just Russia party's Sergei Mironov and independent candidate Mikhail Prokhorov are running for the presidency against Putin, who is currently prime minister.

Putin, predicted to win as much as 66 percent of the vote by independent pollster Levada Center, told a group of chief editors of foreign newspapers on Thursday that opposition leaders in Russia's cities "have not advanced any interesting and well thought-out steps to develop the country".

With Putin's support far ahead of other candidates in the election among the 109 million voters, observers said winning votes in the Russian capital and his own hometown of Saint Petersburg may his greatest challenge.

Putin has unparalleled backing in rural Russia, the hinterlands and small industrial towns, where his "man of action" image has won him support during his 12 years in power.

But Levada Director Led Gudkov said Putin - still Russia's favorite man in the polls - will be a weakened leader, as his popularity shrinks in booming urban centers, where people are increasingly looking for change.

Putin himself on Friday echoed the call by vowing to deepen political reforms if elected president.

"Our proposals are aimed at launching dialogue with everybody, both with our supporters and critics," he told six editors-in-chief of newspapers from France, the United Kingdom, Italy, Germany, Canada and Japan.

Earlier, on Thursday, Putin acknowledged that the number of his supporters is smaller in larger cities. "It means the authorities have to actively react to their demands," he said.

Mikhail Dmitriev, a deputy minister-turned-government adviser who met Putin on Wednesday, told China Daily that Putin and his team, in view of the situation, are willing to make "limited concessions" to the protesters and those unhappy with him in the larger cities.

"We now have a very open political environment basically, there's free debate even on TV in many cases," said Dmitriev, a former first deputy minister of economic development and trade who is now president of the Moscow-based Center for Strategic Research.

Tatyana Zolotova, a 46-year-old housewife, said she has not decided who to vote for yet. The new president should address the issues of inflation and unemployment, and make efforts to boost incomes and raise pensions, she said.

Website designer Alexey Boursakov, meanwhile, said he would vote for Prokhorov, in the hope that a new leadership will eventually emerge and replace the existing one.

It is possible that Putin will not be able to secure half the vote in Moscow and Saint Petersburg, which would mean that the 59-year-old "does not have majority support in major population centers", said Vladimir Frolov, president of government relations firm LEFF Group.

Putin's victory on Sunday, though, appears certain.

Zyuganov, who came in second in Levada's final pre-election polls on Monday, is an unlikely candidate for change. The senior leader is a decade older than Putin and has led his party for 20 years.

The third-favorite in the polls, Zhirinovsky, has been in deep trouble after insulting a renowned female artist in a televised debate on Tuesday with fellow candidate Prokhorov.

Mironov, meanwhile, is the last in the Levada polls with merely 5 percent of the public support. Prokhorov stands slightly higher at 6 percent.

Even in the absence of a peer competitor for Putin, it is worth noting that the "dissatisfied minority" in major Russian cities has the biggest impact on politics, Frolov said.

Frolov, a former deputy staff director of the State Duma Committee on Foreign Affairs and counsel to the deputy chief of the Presidential Administration for Foreign Policy, said it would take an enormous amount of work for Putin to engage the trust of young, Internet-savvy urbanites.

As Putin vowed to fight corruption, create jobs and boost public spending, Russian President Dmitry Medvedev in late February met protest leaders and acknowledged that the country's political system was "far from ideal".

"Depending on how Putin pursues his policies during this six-year term, this number of (urban protesters) will either exponentially grow or they can shrink. It is not a hardline anti-Putin kind of thing. It's sort of a 'desire for change' kind of thing. If some of them see change - there are different definitions of change - they will move to endorse the new Putin," Frolov said.

"Of course, there will be no popular revolt. It's a wrong expectation that there will be an 'Orange Revolution' (which brought pro-Western forces to power in Ukraine in 2004) in Russia. Nobody's thinking about that. There're no resources, no intentions. Nor should it be the objective of the protesters," he added.

Putin's campaign will send 65,000 observers to monitor the elections, while the other four candidates will have a total of about 80,000, according to The Moscow Times. Yabloko will send about 30,000 people as representatives of the party's newspaper.

On Wednesday, Putin said street protests were expected regardless of the election results, and the opposition should respect the voice of the majority.

"People who are talking about the need to develop and strengthen democracy should stick to these rules themselves. The main rule is that the opinion of a minority should be respected, but the majority's choice must be obeyed," he was quoted by Itar-Tass news agency as saying.

Alexander Gorbenko, deputy mayor of Moscow, on Thursday confirmed that a rally by protesters will take place in streets leading to the Kremlin on Monday, the day after the elections.

Moscow Mayor Sergei Sobyanin, meanwhile, said city officials will not allow the protests to drag, like the ones in Kiev in 2004 during Ukraine's "Orange Revolution".