ROME (Reuters) - Italian center-right leader Silvio Berlusconi said on Wednesday he may introduce an amnesty on some illegal construction if his coalition takes power at a national election on March 4.

Keen to avoid taxes and red tape, housebuilders in Italy have long sidestepped regulations, putting up housing that sometimes does not resist the country’s frequent earthquakes and landslides, and clogging picturesque locations.

Berlusconi, who backed pardons for some unlawful building during four previous stints as prime minister, said that such a measure could help cover the costs of his flagship plan for a flat tax.

“I say yes only if the requirement that it was necessary (to build illegally) is strictly applied,” said Berlusconi, whose coalition is tipped to get the most votes but fall short of an absolute majority.

A fifth of the houses built in Italy in 2015 were illegal, according to statistics office ISTAT, a situation that is sometimes blamed on inadequate housing policy.

“Really, we need to change the rules. A person building a house or opening a restaurant or business should not have to wait years for authorizations and licenses any more,” he said.

People should take responsibility for following the rules, and be given time to bring their activities into line if irregularities are identified after the fact, he said.

But the 81-year-old’s main ally, Matteo Salvini of the anti-immigrant Northern League, roundly rejected any amnesty, the latest in a string of policy clashes between the two.

“Our land is already too covered with cement, we need to knock down all the illegal buildings,” Salvini said.

In its shared program, the center-right coalition, which also includes the nationalist Brothers of Italy, has agreed to a halt on all outstanding tax litigation and a reprieve for smaller contributors who have financial problems.

Senate President Pietro Grasso, leader of small left-wing group Free and Equal, condemned the idea of forgiving people who flout building rules, comparing it to “when someone who evades taxes is exonerated because taxes are too high”.

“It is truly criminal to build everything on illegality. No more amnesties,” Grasso said.

If the center-right wins enough votes to be called on to form a government, the parties have decided that whoever gets the most votes will name the prime minister. Berlusconi cannot run himself due to a 2013 tax fraud conviction.