The United States midterm campaign has entered its closing stage, with control of both chambers of Congress hanging in the balance.

All 435 seats in the House of Representatives are being contested, along with 35 of the Senate’s 100 seats. The result will determine whether Republicans maintain congressional control during the final two years of President Donald Trump’s second term or face a Democratic-controlled chamber capable of blocking parts of his agenda.

More than 52 million votes had already been cast before Election Day, according to reporting from the Associated Press. Georgia recorded approximately 2.8 million early ballots, setting a state record for a midterm election.

Trump has been campaigning in Iowa and Kansas, two states he has previously won comfortably. His appearances demonstrate how competitive the political environment has become, with Republicans working to protect their narrow House majority and defend closely watched Senate seats.

The Senate contests in Michigan, Alaska and Maine are among the races attracting national attention. Individual House districts could also become decisive if the national result is close.

In Texas, more than 6.3 million people had voted early as of Wednesday. That compared with 4.2 million at the equivalent stage four years earlier, representing an increase of approximately 50%.

Election organisations are preparing extensive operations to track the results. The Associated Press plans to deploy more than 4,000 reporters to county election offices and polling locations, while other news organisations will rely on verified vote totals and statistical analysis before projecting winners.

The midterms are widely being treated as a public judgment on Trump’s return to the White House. Economic conditions, living costs, immigration, public safety and the administration’s handling of international conflicts have all influenced the campaign.

Voting takes place on November 3. Some races may be called relatively quickly, but close contests, postal ballots and state-specific counting procedures could delay the final balance of power.