Donald Trump upbraided his own Justice Department on Wednesday for slow-walking the production of documents demanded by Congress, suggesting that he might step in personally.

The president has complained about the DOJ's failure to deliver materials that the House Judiciary Committee subpoenaed in March, including what could be millions of pages related to the Hillary Clinton email investigation.

'A Rigged System - They don’t want to turn over Documents to Congress. What are they afraid of? Why so much redacting? Why such unequal “justice?”' Trump tweeted Wednesday.

'At some point I will have no choice but to use the powers granted to the Presidency and get involved!'

President Trump upbraided his own Justice Department on Wednesday for slow-walking the production of documents demanded by Congress

Trump suggested that he might step in personally via 'the powers granted to the Presidency' – perhaps hinting that he could declassify a huge cache of documents so Congress can see them immediately

Attorney General Jeff Sessions has been a regular thorn in the president's side, recusing himself from the entire Russia probe and also presiding over an agency that Trump sees as running at cross-purposes with him

Trump may be angry about Deputy Attorney General Rod Rosenstein's (left) decision to deny congressional Republicans a look at the memo where he spelled out the boundaries of a Russia probe conducted by Special Counsel Robert Mueller (right)

Another potential reason for Trump's tweet is a Justice Department decision this week to withhold from House Republicans a key memo written by Deputy Attorney General Rod Rosenstein, which outlines the authorized scope of Special Counsel Robert Mueller's investigation.

Reps. Mark Meadows and Jim Jordan wanted to see that document, hoping it would strengthen the argument that Mueller has run far outside his original mandate by looking into the president's business dealings and hush-money payments to alleged former paramours.

Trump has also vented on Twitter in the past about the DOJ 'slow walking' documents related to the FBI's applications for surveillance warrants in 2016 and 2017 targeting former campaign adviser Carter Page.

And he's frustrated about the amount of redaction – blacking out – of classified and confidential material when materials are handed over to lawmakers, denying them the chance to see much of what they demanded.

After the Judiciary Committee's April 5 deadline came and went without the DOJ turning over everything under subpoena, Trump tweeted that Capitol Hill Republicans were entitled to see 'UNREDACTED Documents relating to FISA abuse, FBI, Comey, Lynch, McCabe, Clinton Emails and much more. Slow walking - what is going on? BAD!'

House Judiciary Committee Chairman Bob Goodlatte, a Virginia Republican, subpoenaed documents from the DOJ, but the agency ignored his deadline in April

Among the materials Trump and Republican lawmakers are impatient to see are documents related to an abortive probe into Democratic presidential candidate Hillary Clinton's private email server and the classified material investigators found there

He had written three days before the deadline that it was '[s]o sad that the Department of “Justice” and the FBI are slow walking, or even not giving, the unredacted documents requested by Congress. An embarrassment to our country!'

FBI Director Christopher Wray in late March doubled the number of staffers who are singularly focused on finding and evaluating documents that could be responsive to Goodlatte's demands.

Wray agreed in a statement last month that 'the current pace of production is too slow.'

The president has already threatened more directly to insert himself in Attorney General Jeff Sessions' domain on other matters, most notably the DOJ's overall Russia probe and its investigation into the professional conduct of his lawyer-fixer Michael Cohen.

'You look at the corruption at the top of the FBI. It’s a disgrace,' he told 'Fox & Friends' last week.

Trump lambasted 'our Justice Department – which I try to stay away from, but at some point I won’t.'

Goodlatte has succeeded in wrestling one set of documents away from the Justice Department: copies of memos written by fired FBI director James Comey about his meetings with President Trump.

The DOJ handed them over following a public threat to subpoena them.