Bill Pascrell, a congressman representing New Jersey who also serves on the House of Representatives ways and means committee, wrote a letter to the committee’s chairman, Kevin Brady, asking him to obtain Trump’s tax returns based on an obscure tax law (section 6103 of the Internal Revenue Code).

However, all 23 republican members of the committee rejected the proposal.

If a congressional committee was granted access to Trump’s tax returns it could then decide whether to pass them on to the House of Representatives, this would mean that it is highly likely the returns would make their way into the public domain.

In his letter Pascrell said: ‘President Trump is now governing while also owning a business with international investments. The Constitution faces unprecedented threats due to this arrangement.’

At a committee meeting Pascrell said: ‘In 1924, Congress put in place this statute, 6103, in our tax law, specifically to investigate conflicts of interest in the executive branch of government’.

The law gives congressional committees that decide on tax policy the right to examine Presidents' tax returns. The law was passed after the Teapot Dome Scandal, which was a bribery incident that took place during the administration of President Warren Harding in 1921. The law has since been invoked to examine President Nixon’s returns in 1974.

All (excluding one) Presidential nominees since Nixon have released their tax returns to the public (the one who refused, Gerald Ford, released a summary). Trump has continued to refuse to publish his returns and is also the only modern President that has refused to leave his businesses.

Pascrell’s letter to Brady is available here.