Marina Litvinenko, the widow of the defector poisoned in London, led calls for a Ukrainian victory in the year-long war at a noisy demonstration of several hundred outside the Russian embassy in the capital on Saturday. The campaigner was one of several high-profile figures who spoke at a rally across the road from the diplomatic mission in Notting Hill, part of an attempt to highlight Russian opposition to Vladimir Putin’s regime. “The main thing we want is the victory of Ukraine. Only this will bring about the end of the Putin regime and Russia once again being a member of the international community,” Litvinenko said in a short address in Russian that ended with her calling out “Slava Ukraini” – glory to Ukraine. Speaking to an audience crammed tightly on the pavement nearby, Litvinenko said she “didn’t expect to see so many people at a protest of this kind”, in which people marched from Marble Arch for an hour to reach the embassy in west London. Her husband, Alexander, a former Russian spy, was poisoned with radioactive polonium in London in 2006, probably, a British public inquiry concluded, on the personal orders of Putin. After his death, dramatised in a recent ITV series, Marina campaigned for a proper investigation into his murder. Another speaker, the businessman Mikhail Khodorkovsky, jailed for more than a decade as the Kremlin seized control of his Yukos oil company, said the demonstration showed that “Russians, Russian citizens, have completely different interests” from Putin and what he described as his war of aggression. “Nobody except Putin needs this war. A lot of people believe that Russians and war are synonymous. That’s not right. It’s Putin’s war, not the war of Russian people or Russia,” he said. “We understand the end of the war means the end of the Putin regime. Russia will be free! Glory to Ukraine!” The organisers, the Russian Democratic Society, estimated that 700 people participated, although space outside the embassy itself was limited because the Metropolitan police had refused to close the busy A40 main road outside. Ksenia Maximova, the director of the campaign group, said the protest demonstrated the existence of coordinated expatriate opposition to Putin, which has struggled to be visible as the war runs into its second year. “Everyone always says that Russian opposition is not united, we can’t unite, we don’t have a leader, but this proves that we don’t need a leader as such,” she said. “When people starting saying that Russians are not coming out, where are they? Well, they are right bloody here.” Other speakers included Bill Browder, an American financier, who became an anti-corruption campaigner after his lawyer, Sergei Magnitsky, died in a Russian jail, and Vladimir Ashurkov, who helps run the Anti-Corruption Foundation, founded by the jailed opposition leader, Alexei Navalny. The Russian embassy has become a focus for protest since the war began. Earlier this week, the anti-Brexit group Led By Donkeys painted the road in front of the embassy yellow and blue, to represent the Ukrainian flag, and the paint was still visible as the cars drove past on Saturday. On Friday evening, a small group from the Russian Democratic Society also projected the words “Russia is a terrorist state” on to the front of the embassy in a late-night stunt that ended with a brief confrontation in the street. Embassy staff, including, Maximova said, the ambassador, Andrei Kelin, came out of the building to find out what was happening, but refused to engage with the handful of protesters present on the street. Instead, she added, Kelin personally filmed the demonstrators. The footage, she believed, would be sent back to the Kremlin. A spokesperson for the Russian embassy said “of course we have our own footage” but dismissed the suggestion that Kelin was involved, and added the ambassador had “nothing to do with that”.