Virginia voters have approved a redistricting measure that could hand Democrats control of the thinly-divided US House of Representatives, US media report. The state is the latest front in a national battle to redraw congressional districts after President Donald Trump and Republicans initiated a national gerrymandering push aiming to help conservatives maintain a congressional majority.

Democrats in California last year approved a similar measure to change the state's voting districts, with the goal of cancelling gains made by Republicans in redrawn maps in Texas. Virginia's passed amendment will redraw the state's congressional map to flip as many as four House seats held by Republicans.

Democrats currently hold six out of the state's 11 seats, and the updated map could allow them to hold up to 10. This redistricting referendum is the most expensive ballot measure in Virginia's history, with over $80 million raised by groups on both sides of the effort.

Trump expressed concern, stating that if House Democrats win a majority in the midterm elections, it would be 'a disaster.' He remarked, 'I don't know if you know what gerrymandering is, but it's not good.'

States usually redraw their voting maps every decade after the US Census, but Texas initiated mid-decade changes under Trump’s influence, prompting other states, including Virginia, to follow. California's new maps approved in November also aim to solidify Democratic advantages, reflecting a wider trend of gerrymandering in U.S. politics.