MANCHESTER, N.H. -- The husband of White House counsellor Kellyanne Conway has donated to one of U.S. President Donald Trump's Republican primary challengers.

According to Federal Election Commission filings, George Conway donated US$5,600 to former Illinois congressman Joe Walsh's 2020 run on Aug. 30.

Conway, an attorney, has been critical of Trump during his presidency. In March, Trump tweeted that Conway is "a stone cold LOSER & husband from hell!" For his part, Conway has questioned the president's mental health and described Trump's presidency as "maddening to watch."

In addition to Walsh, former Massachusetts Gov. Bill Weld and former South Carolina governor and congressman Mark Sanford are also running against Trump in the Republican presidential primary.

Several states have decided to cancel their Republican primaries ahead of the 2020 election, an effort that helps smooth Trump's path to reelection.