By Kylie MacLellan
LONDON (Reuters) - Britain's opposition Labour leader Ed Miliband promised to crack down on immigration if his party is elected next year, seeking to woo voters tempted by the anti-EU UK Independence Party (UKIP), which could threaten his chances of winning power.
The increasing popularity of UKIP, which wants tighter immigration controls along with an EU exit, has pushed Britain's main parties to take a tougher line.
Labour has traditionally been more positive towards immigration than its political rivals and its last period in power, from 1997 to 2010, saw high rates of immigration.
Last week Prime Minister David Cameron also hardened his line on the issue, saying more needed to be done and promising he would outline new plans in the coming weeks.
His governing Conservative Party has already lost two of its lawmakers to UKIP, which won its first parliamentary seat earlier this month and is on course to win a second on Nov. 20, according to a poll on Thursday.
Speaking in southeast England where that single-seat vote is taking place, Miliband promised a Labour government would introduce new laws on immigration in its first year, including preventing recruitment agencies hiring only from abroad.
Greater controls would be put in place at borders to keep track of who has come in and out of the country, he said, also pledging to seek EU reforms including lengthening the period before migrants are entitled to claim welfare payments.
"Our plan to make this country work for your family also includes addressing immigration," Miliband said, adding that he would set out further plans on immigration in the coming months.
"We should seek to tackle the concerns that people have ... We must understand these are real issues and show that we are ready to act on them. That is why I have changed Labour's approach on immigration."
The rise of UKIP, support for which nationwide polls have shown reaching a record high of 25 percent, not only threatens Cameron's re-election drive by splitting the right-wing vote, but also poses a challenge to left-leaning Labour.
Earlier this month Labour narrowly retained a parliamentary seat in its traditional heartland in northern England, with UKIP coming a close second with almost 39 percent of the vote, up from less than 3 percent in 2010.
While Labour is slightly ahead in nationwide polls of voting intention for the 2015 election, some in his party worry Miliband's poor personal ratings are an electoral liability.
A YouGov poll on Thursday showed just 16 percent of people thought Miliband would make the best prime minister, equal to his lowest-ever ranking, last hit in January 2012, and compared to 36 percent of people who favored Cameron.
Miliband has been derided for forgetting vital parts of his address to his party's final pre-election annual conference last month, including the section on immigration, despite it being one of voters' top concerns.
(Editing by Stephen Addison and Andrew Roche)