As the former general counsel of the U.S. House of Representatives who won the first court action to enforce a subpoena against the executive branch, I caution that the expected onslaught of subpoenas in the next Congress may not be as effective as expected in uncovering the secrets, excesses and seamy sides of the Trump administration.

Subpoenas are not self-enforcing. If subpoenas are ignored or disobeyed, there needs to be an effective mechanism to compel compliance. Before 2008, there were only two recognized ways to enforce a House subpoena: invoking inherent contempt, involving internal processes of the House; or seeking a criminal prosecution by the Justice Department.

Inherent contempt authority permits the House sergeant-at-arms to arrest the resisting party and bring him or her before the full House for a trial. If adjudicated in contempt, the person can be placed in prison until the contempt is cured or the session of Congress expires. This approach was approved by the Supreme Court in the early 19th century but has not been used since the early 20th century because of its obvious disadvantages and political unpalatability. The House doesn't even have a prison.

Criminal contempt is initiated by the speaker transmitting a certification of contempt to the U.S. attorney for the District of Columbia. Under the pertinent statute, the U.S. attorney is required to present the matter before a grand jury for the return of a felony indictment. Conviction would result in a prison term and/or fine. However, when it is an administration official who is carrying out the president's policy in disobeying the subpoena, the Justice Department almost certainly will not prosecute.

That was the case in 2008, when the George W. Bush administration claimed that its top staff aides were immune from House subpoenas seeking to investigate suspicious firings of U.S. attorneys. On behalf of the House, I filed a civil action in federal court to enforce the subpoenas. Failure to comply with the resulting court order would have resulted in contempt of court, enforceable by imprisonment. A favorable ruling by the court also would have given the House an important advantage in the court of public opinion.

This worked effectively in 2008 in large part because, after a favorable prompt ruling by a courageous District Court judge, a new administration came into office. During the appeal, the House was able to work out a satisfactory compromise with the White House that resulted in the taking of testimony and the production of many subpoenaed documents.

But the litigation approach is likely to be less effective with two years to go in the Trump administration. This administration, led by a president who has refused to release his tax returns, contrary to all recent precedents, and an acting attorney general who disregarded a subpoena from the Federal Trade Commission investigating fraud by a company on whose board of advisers he served, is likely to put up strong resistance to House subpoenas. The administration's actions to seek endless delays in the trial of the pending census case - leading the federal trial judge to issue a strong public rebuke for its unjustifiable motions - are likely a foreshadowing of the tactics one can expect in response to House subpoenas. Delays beyond the 2020 elections will be the goal.

As a result, if it wants timely compliance with its subpoenas, the House will have to augment an expedited litigation approach with a willingness to bring to bear all of its political muscle against the executive, exactly as our Constitution contemplated. The House will have to use the power of the purse and its legislative options - such as not voting on administration-desired bills - to ensure that its subpoenas are complied with in a timely fashion. The House will also have to prioritize its efforts - choosing just one or two subpoenas to pursue, to keep the public focus on the most important and pressing demands for information and on the administration's unjustified resistance.

It is even possible that the House will have to dust off its inherent contempt authority, preparing the sergeant-at-arms and his staff to train for arrests and contracting with the District of Columbia corrections authorities to ensure that there is space at the D.C. jail to accommodate those who might be disposed to disregard or delay compliance with House subpoenas.

Irvin Nathan was the general counsel of the U.S. House of Representatives from 2007 to 2010.