A charismatic leader of Russia\'s protest movement said he would be ready to take on Vladimir Putin in fair presidential elections, as an ally said that the Russian premier was ready for dialogue. Putin is facing the biggest challenge of his 12 year domination of Russia as he heads into March 4 presidential elections after two mass protests against the conduct of allegedly rigged parliamentary polls. Alexei Navalny -- a lawyer who won prominence in Russia with investigations of state corruption and a ferociously anti-Putin blog -- has emerged as one of the most charismatic leaders of the nascent protest movement. He can no longer register for March 4 presidential elections because the registration period expired earlier this month but he told Moscow Echo radio in an interview he would challenge Putin if the elections were fair. \"I am ready to fight to make sure that we get fair elections,\" Navalny told Moscow Echo radio. \"When we get a chance to take part in elections, I am ready to fight for leading positions, including in the presidential vote,\" he said in the interview late Monday. Navalny said he would be pushing demonstrators to come out for even bigger rallies that force the authorities to delay the presidential vote until current political party restrictions are lifted. \"This vote that we will be having will not be an election. They will be illegitimate no matter what happens. We will never recognise them,\" Navalny said. His comments came as an old ally of Putin said Tuesday that the prime minister was ready to listen to the growing protest movement and make sure that March presidential elections in which he is favoured are fair. Former finance minister Alexei Kudrin told the Vedomosti daily that he met Putin -- who has announced plans to swap jobs with President Dmitry Medvedev after the March vote -- on the eve of the latest mass rally in Moscow. \"From my conversation with Putin, I understood that he was not afraid of the March 4 elections. He is ready to take all the measures necessary to make sure these elections are fair,\" Kudrin told the business daily. Kudrin said he told Putin that \"urgent dialogue was needed\". \"This is what I told Vladimir Putin before coming to the rally. On the whole, I understood that this dialogue was possible,\" added Kudrin, who was nonetheless whistled at the rally as a member of the ruling class. Tens of thousands of Russians rallied in central Moscow for the second time in two weeks against the outcome of December 4 parliamentary elections that Putin\'s ruling United Russia party narrowly won with the alleged help of fraud. Saturday\'s action was both bigger and more directly aimed against Putin than the first protest on December 10. The leaders of the protest movement have not yet said when the next demonstration will take place but have indicated it will not be before the end the of New Year holidays in mid-January. However huge anger has been sparked by the handing of an additional 10-day jail sentence handed to Sergei Udaltsov, an ultra-left wing activist who had already served a term in prison for taking part in a rally earlier this month. Udaltsov has been on hunger strike to protest his repeated arrests by the authorities and the opposition has expressed increasing concern about his health. Over 1,700 people vowed on Facebook to attend a rally on Thursday on Pushkin Square in Moscow \"for the release and life of Udaltsov and all political prisoners\" but the action has not yet been authorised by the authorities.