KUALA LUMPUR, May 1 (Reuters) - Malaysia"s Prime Minister Najib Razak promised on Tuesday to raise the minimum wage this year if he wins the May 9 general election, adding to a raft of promises to voters as he faces a resurgent opposition. Najib"s former mentor, Mahathir Mohamad, now leads an opposition alliance united in the goal of unseating the prime minister and his Barisan Nasional (BN) coalition, which has ruled since the country gained independence from the British in 1957. Najib told a Labour Day rally that he would raise the minimum wage from the current 1,000 ringgit ($255) per month in peninsular Malaysia and 920 ringgit in the eastern states of Sabah and Sarawak, if his coalition wins the polls. "So if you want the minimum wage rate to be raised, you know what to do. Do we have a deal?" he said to cheers from some 2,000 people gathered at the rally. Najib also announced 200 million ringgit for a skilled workers programme, an additional 60 million ringgit allocation for an insurance plan for retrenched workers and better maternity benefits for private sector workers. Najib said this was all part of his administration"s efforts to better the lot of the country"s workers over his nine years in charge. "If the Barisan Nasional government is a flower, the workers are the stem. Hence, do not be drawn to and drink from another "flower"," he said, in a thinly-veiled reference to the logo of Mahathir"s new party. Campaigning officially kicked off on Saturday, and Najib has since crisscrossed the country opening new schools, meeting voters and promising aid and benefits to voters in mostly rural constituencies that form the bedrock of support for his ruling coalition. This general election, Malaysia"s 14th, is arguably the toughest faced by Najib"s undefeated coalition. Besides the challenge from the 92-year-old Mahathir, Najib is also grappling with a multi-billion dollar scandal at state fund 1Malaysia Development Berhad (1MDB) and anger over rising living costs. BN are widely expected to retain power, but a weaker majority in the 222-seat parliament could leave Najib open to an internal leadership challenge.