WASHINGTON (Reuters) - The US Congress plans to amend its domestic law at the initiative of Islamist MP Elhan Omar, who won the mid-term elections to allow the veil to be worn at his headquarters, backed by the world's leading Muslim rights group.

Ilhan Omar, a former Somali refugee who won a seat for Democrats in the election earlier this month, has been drafting the ban, which has for 181 years banned headscarves in Congress. The new version will allow exceptions for religious reasons and apply to the headscarf of Muslims and the skullcap of Jews and the turban of Sikhs.

The amendment is expected to be passed by the US House of Representatives, which is now the majority of Democrats.

Elhan Omar said on Twitter that wearing the headscarf was her choice and "is an option protected by the first amendment to the constitution."

"This is not the only block I want to abolish," said a woman from Minnesota, one of two Muslim women who won midterm elections.

The Council on American-Islamic Relations expressed support for the proposal "which puts the House of Representatives in harmony with the Constitution and the protection of religious freedom."

Democrat Jim McGovern, who is supposed to chair the commission charged with voting on the new domestic law, said the change reflected Congressional pluralism.

He explained that the law "will stipulate that no restrictions should be prevented by a member of the Council from performing his work on which he was elected because of his religion."