At a noisy Chinese restaurant in east Vancouver this week, the former Liberal Party prime minister had no problem making himself heard above the din as dim sum was being served. Paul Martin reminded the partisan crowd that before losing the last election, his minority government pushed for trade and tourism agreements with China and signed a technical-exchange deal with India. 'Stephen Harper turned his back on that framework agreement with China and ignored that agreement with India,' said Mr Martin, who resigned as leader after losing to the Conservative Party in 2006 and is not running in this election. 'When you look at what's happening with the world today, you don't turn your back on China and you don't ignore India.' Mr Martin made a point of saying he has made trips to Asia in contrast to Prime Minister Harper, who has been criticised for not leading a delegation to China during his 21/2 years in power. With the current prime minister leading in public opinion polls, the Liberal Party is reaching back to a base of support that has been steadily eroding - the ethnic and immigrant communities. Vancouver resident Harbir Batra has always voted Liberal, but he said the Conservatives were making a big push to win the votes of ethnic South Asians. 'I'm not tempted to go, but I know people are because the Conservatives say they're in power and there's more they can do than the Liberals,' Mr Batra said. The Conservatives have made a concerted effort since taking power in 2006 to attract this crucial voter base. Mr Harper made a point of beginning his campaign at the home of Edwin Huang, his wife Fei Chen and their two children, in Richmond, a suburb of Vancouver. The family immigrated from China in 2000. 'This party reaches out to all Canadians, to all regions, to all ethnic backgrounds and to all genders,' Mr Harper said. 'When I meet and I see the Huang family, first and foremost they're middle-class families who face most of the same challenges and opportunities that every middle-class family faces. We want to make sure our policies address their concerns as much as any other family in Canada.' Mr Huang said the prime minister's message of helping families hit home for him. 'The most important thing for me is my family, and his relationship with the Chinese seems OK,' Mr Huang said. Including ethnic groups, Mr Harper says, has been a priority for the Conservative Party since it rebuilt itself - after fracturing in the 1990s then merging with a reformist faction based in western Canada. One of the obstacles to his winning a parliamentary majority, he says, has been the minority vote - traditionally Liberal Party supporters. That's a major reason, even though the Conservatives have a strong base across Canada, they have not made major inroads in the urban constituencies where the country's immigrant populations have mainly settled. In cities such as Toronto and Vancouver, the prime minister said, Conservatives had been unable to win those seats not because 'there are more Liberals, but [because] conservatives don't vote Conservative, especially new Canadians'. New Canadians have generally gravitated towards the Liberal Party, which was in government during times of mass immigration in the 1960s and 1970s. But now that voter base is splitting. In a by-election last spring in the Vancouver constituency of Quadra, the Conservative candidate lost but the party noted a rise in the number of Chinese voters who came its way. Now the Liberals are making a big push in such cities as Richmond - where the Chinese population is more than 40 per cent - and in east Vancouver, to entrench or bring back their supporters. During the past week, Mr Martin has been campaigning in Vancouver. In nearby Richmond and Surrey, where the South Asian population is dominant, Justin Trudeau, the son of the late, former Liberal icon Pierre Trudeau - considered by many to be instrumental in Canada's multiculturalism policy - came to town to help local candidates. Mr Trudeau, who is running for a seat in Montreal, reminded voters of his father's line that 'Canada is so good not in spite of its diversity but because of its diversity'.