The US Justice Department has said it plans to sue the state of Texas to block a law which requires proof of citizenship to vote.

The announcement was the latest volley in a nationwide battle over controversial voter ID laws, which critics say disenfranchise immigrants, people of colour and the elderly.

Attorney General Eric Holder said on Thursday that the action marks another step in the effort to protect voting rights of all eligible Americans.

He said the government will not allow a recent Supreme Court decision to be interpreted as "open season" for states to pursue measures that suppress voting rights.

On June 25, the Supreme Court threw out the most powerful part of the Voting Rights Act, whose enactment in 1965 marked a major turning point in black Americans' struggle for equal rights and political power.

'Preventing voter fraud'

In a press release, the Justice Department also stated that it will separately intervene in Texas' redistricting laws.

The release stated that both state laws were adopted with the "purpose, and will have the result, of denying or abridging the right to vote on account of race, colour, or membership in a language minority group".

The statement came one day after Kansas and Arizona filed a lawsuit against the US government in an attempt to secure the right to exercise their own voter ID laws.

The Republican-led states accuse the US Election Assistance Commission, an agency of President Barack Obama's administration, of preventing them from enforcing the laws, which they say are aimed at preventing voter fraud.

The federal form now asks for a verbal pledge that the applicant is a US citizen, but does not require documentation as proof.

A number of states led by Republicans have tightened voter identification laws in recent years, prompting criticism from Democrats and some advocacy groups that they will discourage minorities, the elderly and the young from voting.

Source: Agencies