• The Dem-controlled House Ways & Means Committee will decide whether to release Trump's tax returns.
• The congressional panel went into a closed-door session on Tuesday afternoon.
• Democrats have been working since 2015 to gain access to the former president's financial documents.

Boxes of former President Donald Trump's tax returns got the ceremonial treatment on Tuesday as they were wheeled into a key House Ways & Means Committee hearing in a little blue wagon.

Lawmakers on the committee are set to vote Tuesday whether to publicly release Trump's returns, which he kept confidential during his campaign and presidency in a buck of recent tradition.

The Democratic-led committee officially gained access to the documents, which span 2015-2020, in November after the Supreme Court rejected Trump's emergency request to block the panel from obtaining the records.

Democrats are coming down to the wire on whether or not to make the documents public in the final days of the year. Republicans will take control of the House of Representatives come January.

The closed session began at 3 p.m. ET and could continue late into the evening. It was unclear when exactly the returns would be released if the committee decides to make them public.

Democrats on the committee have long been working to gain access to the former president's financial documents spanning from 2015 to 2020, while Republicans have framed the Democrats' fight as politically-motivated.

While much has been reported on Trump's finances in the intervening years, questions still remain about the entrepreneur's wealth and financial dealings with foreign countries and individuals that could be revealed in the documents.