A federal court has blocked an attempt by Texas to redraw its electoral maps after the US justice department said the move was intended to diminish the impact of the Latino vote.

The US attorney general, Eric Holder, had described the proposed changes as part of a broader attack on civil rights by states trying to roll back laws ensuring the right to vote using redistricting, voter identity card laws and other tactics.

The issue may now end up before the US supreme court as part of a legal challenge by Texas and other states to voting rights legislation.

The Republican-dominated Texas legislature last year redrew constituency boundaries to create new electoral districts after the latest census showed that the state's population grew by more than 4 million in a decade. That entitled Texas to four more members of Congress.

Democrats said that the new electoral maps were manipulated to diminish the fact that minorities account for most of the population increase. Latino voters lean heavily toward voting Democrat while the boundaries were redrawn to ensure the additional seats would be won by Republicans.

In May, Holder said that in Texas "electoral maps were manipulated to give the appearance of minority control while minimising minority electoral strength".

A Washington DC court on Tuesday agreed with the federal government that the new maps did not comply with the 1965 Voting Rights Act, a key piece of civil rights legislation designed to put an end to practices that deprived minorities of the ballot or diminished the effect of their votes.

Texas is one of 16 states, mostly in the south, that under the act must obtain US justice department approval for changes to voting laws or procedures because of a history of racial discrimination.

Trey Martinez Fischer, a Texas state legislator with the Mexican American Legislative Caucus, welcomed the ruling. "This is absolutely a victory for Texas and for minority voters to elect a candidate of their choice," he said.

The Texas attorney general, Greg Abbott, said he will appeal against the decision to the US supreme court. "Today's decision extends the Voting Rights Act beyond the limits intended by Congress and beyond the boundaries imposed by the constitution," he said.

"The attorney general's office will continue defending the maps enacted by the Texas legislature and will immediately take steps to appeal this flawed decision to the US supreme court."

Texas and five other states have already asked the US supreme court to strike down the section of the voting rights act requiring permission from the justice department for changes to electoral law. The states argue that while the requirement once served "a noble purpose" it is now outdated and that its "benefits have all but vanished".

The decision will not have an impact on November's elections, which were already to be conducted using interim maps drawn up by a federal court in San Antonio. But the legal fight will decide districting at future ballots.

In May, Holder characterised the move by Texas as part of a broader attempt by a number of states to roll back civil rights era gains including requirements for voters to show photo identification at the ballot box which poorer people and minorities, who tend to vote Democrat, are less likely to have.

"Now unfortunately, electoral redistricting is far from the only area of concern in covered jurisdictions. The recent wave of changes to state-level voter identification laws also has presented a number of problems requiring the (justice) department's attention," he said.