MANILA, Jan 16, 2013 (AFP) - The Philippines is set to regulate Internet advertising in May mid-term polls as part of an effort to rein in campaign spending, an election official said Wednesday.

As part of the regulation, candidates for the upcoming elections will be limited to three days of online adverts per week, Commission on Elections spokesman James Jimenez said.

Filipinos are due to elect thousands of local officials ranging from governors to senators on May 13.

"Even pop-up ads or buttons. No matter the size. If a politician were to take out an ad on an online version of (a newspaper), it can only be shown three days out of every week," he told AFP.

He said the commission was prompted to take this action after a huge surge in unregulated online political advertising during the 2010 national elections.

Jimenez also said Internet advertisements would fall under official limits on election spending for each candidate along with traditional ads in newspapers, television and radio.

However he said candidates will be allowed to maintain their own websites and not have it charged against their election spending limit.

"It (the website) is like a campaign headquarters. We don't regulate headquarters, what kind of banners they have, their furnishings," he said.

Local candidates are normally allowed to spend at least three pesos (seven cents) per registered voter in their areas, Jimenez said.

But political analysts say that spending limits are easily circumvented in Philippine elections where huge amounts of money are disbursed for advertising, campaigning, rallies and even outright buying of votes.

Critics also charge that the huge amounts required to win an election in the Philippines ensure that only wealthy, influential figures can run for office.