Senate Majority Leader Mitch McConnell Addison (Mitch) Mitchell McConnellObama calls on Senate not to fill Ginsburg's vacancy until after election Planned Parenthood: 'The fate of our rights' depends on Ginsburg replacement Progressive group to spend M in ad campaign on Supreme Court vacancy MORE (R-Ky.) on Tuesday became one of the highest-profile Republicans to call for Donald Trump Donald John TrumpObama calls on Senate not to fill Ginsburg's vacancy until after election Planned Parenthood: 'The fate of our rights' depends on Ginsburg replacement Progressive group to spend M in ad campaign on Supreme Court vacancy MORE to release his tax returns.

"For the last 30 or 40 years, every candidate for president has released their tax returns, and I think Donald Trump should as well," McConnell told Business Insider.

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Trump has faced pressure from Democrats and some Republicans to release his tax returns since becoming the GOP’s presumptive presidential nominee.

The businessman has insisted he'll release his tax returns once an Internal Revenue Service audit is complete and says he hopes that audit is finished before the November elections.

Mitt Romney, the GOP's 2012 nominee, has pushed Trump to release his returns, claiming they likely contain a "bombshell" about the businessman's finances. Romney faced similar attacks over his tax returns when running against President Obama.

Earlier in May, McConnell hinted that Trump should release his tax returns, pointing to the "tradition" of major presidential candidates releasing them.