A win for the Democrats in Congress next year will cause problems for the Donald Trump administration that may even result in the president resigning from his post, a political risk analyst has suggested.

"If the Democrats win in 2018 as far as the House of Representatives, they can then actually publish the tax returns of the president," John Raines, head of political risk at IHS Markit, told CNBC.

"So is there something in those tax returns that could actually cause damage to the president? All of a sudden he feels compelled to do something like resign."

If the Democrats gained a majority in Congress, they could take control of certain Congressional committees. Some of these committees have the power to request anyone's tax returns, including those belonging to the president. These committees could then share the returns with other members of the committee or make them public.

The president's tax returns have been a hot button political issue since the election campaign, when Trump became the first major presidential candidate since the 1970s not to release his tax returns. The president claimed he could not release them because he was under audit by the IRS.