Washington: Republicans will hold on to their majority in the US House of Representatives as expected, networks projected Tuesday, as attention shifts to the Senate where the battle for control is tighter.

With the US election in full swing, the party of populists presidential candidate Donald Trump was on track to take 235 seats to the Democrats’ 200, according to NBC’s House model.

That would be a 12-seat gain for Democrats, but still far short of what would be necessary to snatch the chamber back from Republican control.

By holding the House, Republicans secure a policy check on Hillary Clinton in the event she wins the presidency.

And, if Trump wins, it will be far easier for the chief executive to push through legislation that he or she wishes.

The Senate, where 34 of the 100 seats are in play Tuesday, is also in Republican hands, but under sharper threat of a Democratic takeover.

With that chamber currently 54 to 46 in the GOP’s favour, Democrats need to gain five seats for a clean majority.

In the event the Senate is 50-50, control goes to the party that wins the White House, because the US vice president serves as the deciding vote in the event of a tie.

Democrats claimed a quick pick up Tuesday in Illinois, where two-term congresswoman and Iraq war veteran Tammy Duckworth defeated incumbent Senator Mark Kirk.

But Republicans bolstered their chances to hold the upper chamber when Senator Marco Rubio, a former Trump rival in the Republican primaries, fought off a challenge in Florida to keep his seat.

A handful of other Senate races with Republican incumbents, in states like Wisconsin, Pennsylvania, New Hampshire and North Carolina, are considered tossups.