President-elect Vladimir Putin urged his opponents on Wednesday to bury their differences with him for the sake of Russia's economic and political future after months of protests and elections that divided the country.

But some deputies walked out when he deflected criticism over a disputed mayoral vote after his last speech to parliament as prime minister, underlining the challenge he faces from the opposition after the biggest protests of his 12-year rule.

The 59-year-old leader, who for many years faced little overt criticism, could hardly keep his temper when challenged over meat production, raising his voice and pointing angrily at a deputy who interrupted him during questions after a 1-1/2 hour speech hailing the achievements of his four years in government.

We have one Russia, and its modern, advanced development must be the goal that unites all the country's political forces that want to work to build it, Putin told the Duma to occasional bursts of applause during a nearly four-hour session.

The country has gone through a tense period of parliamentary and presidential elections. And today the echoes of the heightened emotions and political battles can still be heard, he said.

But the logic of a mature democracy is that elections end, and afterwards a far more important period of joint work always begins.

Putin did not say who he would bring into government when he starts his six-year term as president on May 7 but said policy must be aimed at improving the business and investment climate, boosting economic growth, creating jobs, strengthening Russia's global standing and helping the population grow.

His speech, delivered unsmilingly from a podium to rows of seated deputies, was laced with populist references to Russia's sovereignty, economic progress and ability to act alone on the world stage.

But although his authority has been dented by the protests, which brought tens of thousands of people on to the streets of Moscow before losing steam, he offered no new concessions to opponents who accuse him of stifling dissent.

DEPUTIES WALK OUT

The former KGB spy has offered limited political reforms making it easier to register parties in response to the demonstrations, sparked initially by anger over alleged electoral fraud. In response to a question on Wednesday, he did not rule out bringing opposition members into government.

But his opponents, who fear he could seek another term when his presidency ends in 2018 and go on to rule until 2024, have dismissed his concessions as token changes that do nothing to end his domination of the political system.

Putin, who is about to start his third term in the Kremlin, risked heightening their frustration by saying he considered it reasonable to limit the president to a total of two terms but suggesting it would not apply to him because it would not be retroactive.

This concerns me less, he told deputies during questions.

Several deputies walked out when Putin suggested a Just Russia party member who is on hunger strike over alleged fraud in a mayoral election in the southern city of Astrakhan should take his dispute to court instead.

Losing candidate Oleg Shein has been on a hunger strike along with several supporters for nearly a month to protest the official result of the election in the southern city of Astrakhan which he lost to a rival from a pro-Kremlin party.

As far as I know, your colleague Shein started the hunger strike but did not appeal to court. This is a bit strange. Why go on hunger strike? Putin said when a Just Russia deputy asked his opinion of the dispute.

Making clear his party had no faith in the Russian legal system, Just Russia leader Sergei Mironov later told the Duma: Our friends in Astrakhan have no illusions about the objectivity of the Astrakhan courts.

Kremlin critics say courts are subject to pressure from the government and have had little success contesting results of December's parliamentary election won by Putin's party.

Putin sat looking down and making notes as Mironov took the podium and criticised him over the case.

In a further sign of his unease with an assembly emboldened by the demonstrations, even though most of the protest leaders do not have seats there, Putin angrily told the deputy who took him on over meat production to sit down.

Before his address, police had detained leftist opposition leader Sergei Udaltsov and five other demonstrators as they tried to stage an anti-Putin protest outside the Duma.

RUSSIA IS STRONGER THAN BEFORE

Russia's economy is in moderate recovery after the 2008-09 global economic crisis, and Russia won praise for building up a big rainy-day fund that helped prevent economic meltdown.

But concerns are mounting that Putin's pre-election spending pledges will make the public finances of the world's largest energy producer more vulnerable than ever to an oil-price crash.

Putin said it was crucial to make Russia better for business and more attractive for investors, warning that if we do not correct the situation in the business climate, we cannot resolve a single task we face in the economy and the social sphere.

Putin, who has said he will name outgoing President Dmitry Medvedev as prime minister in a job swap with the protégé he helped into the Kremlin in 2008, said his spending plans had been carefully calculated and defended his policies in general.

Evaluating the results of the last four years, we can rightly say Russia has not only overcome the crisis, he said. We are stronger than before.

Drawing comparisons with the chaotic 1990s under President Boris Yeltsin, when Russia needed an international bailout after defaulting on its debt, he pledged to build a new economy that could withstand external shocks without help from outside.

He said Russia must create jobs, vowed to increase average real wages by at least 60-70 percent by 2020, and said he would diversify the economy. He called for bold, new steps to tackle demographic problems which experts say could harm economic growth in the country of more than 140 million.

Economic analysts welcomed the promise to improve the investment climate but said Putin had much to prove.

While we see this as very encouraging, we repeat ad nauseam a message that we have been projecting for a very long time now, that the economy may face serious structural headwinds in the middle of Putin's third term, said Ivan Tchakarov of Renaissance Capital in Moscow.

(Writing by Timothy Heritage, Editing by Steve Gutterman)