ISLAMABAD (Reuters) - Government and opposition lawmakers scuffled in Pakistan's parliament on Monday as tempers frayed after last week's arrest of an opposition leader on charges of defaming the military.

The scuffle, in which about a dozen parliamentarians pushed and shoved each other, comes after a year-long noisy stand-off between the government and opposition over the powers given to president and army chief General Pervez Musharraf.

About 80 opposition members stood in front of the speaker of the national assembly, or lower house of parliament, on Monday shouting slogans against Musharraf and seeking the release of their detained leader.

Makhdoom Javed Hashmi, de facto leader of the Pakistan Muslim League led by exiled former prime minister Nawaz Sharif, was arrested by the authorities on Wednesday, on accusations that he had defamed the military and tried to incite mutiny.

The opposition, including secular and hardline Islamic groups, is demanding that Hashmi be brought to the national assembly without delay. Some government members tried to remove the banners they were carrying when the scuffle broke out.

However, others intervened to prevent a full-scale brawl.

The opposition wants Musharraf, who took power in a bloodless coup in 1999, to resign as army chief and to submit to parliament constitutional amendments he made before elections last year.

The opposition has disrupted parliamentary proceedings and staged walkouts in order to press its demands.

Political confrontation has prevented Pakistan from being re-admitted to the 54-nation Commonwealth group and remains a key negative factor in attracting foreign investment despite strong economic fundamentals.