LISBON, June 28 (Xinhua) -- Portuguese President Anibal Cavaco Silva on Monday signed into law a bill containing a package of austerity measures to reduce the public deficit.

The law, which was first presented by the government and later approved by the parliament, included an increase of value added tax and taxation on companies and workers.

Some people doubt whether some measures in the law are constitutional.

The Constitutional Tribunal is expected to decide soon whether the measures are constitutional.

The government aims to reduce the public deficit this year from 9.3 percent to 7.3 percent of gross domestic product.