Washington (CNN) Conservative lawyer George Conway, the husband of White House counselor Kellyanne Conway, has donated to one of President Donald Trump's Republican rivals: former Illinois Rep. Joe Walsh.

Federal Election Commission filings show that Conway donated $5,600 on August 30 to Walsh's longshot bid to grab the Republican nomination from Trump.

Walsh raised about $129,000 between August through September -- compared to Trump and the Republican National Committee's $125 million haul during the July-to-September fundraising quarter.

The former Illinois congressman revealed last month to CNN that Conway is informally advising his 2020 campaign.

Conway has been a frequent critic of the Trump administration, in which he nearly took a job -- and in which his wife is a prominent figure.

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