Actor Fred Thompson is leaving his role on Law and Order for a possible run at the white house, according to media reports Wednesday.Washington - Actor Fred Thompson is leaving his role on “Law and Order” for a possible run at the white house, according to media reports Wednesday.

Dick Wolf, The executive producer of the show, confirmed that Thompson will be leaving the long running TV Show.

Wolf said the former Tennessee senator told him he “has not made a firm decision about his political future,” but the shows production schedule would create constraints.

NBC is owned by General Electric Co.

His expected entrance in the race could dramatically shake up the GOP field but it’s unclear exactly who among the top GOP candidates - Giuliani, McCain or Romney - would be affected the most by his candidacy.

Conservative voters are not sold on any of them, which may give Thompson an opening. He’s been casting himself as a straight-talking conservative in the mold of former President Reagan even though he took some positions that angered the base as a senator.

Thompson served in the Senate from 1994 to 2002, capturing the seat held by Al Gore in a special election. During his tenure, Thompson voted to oust President Clinton from office, but also was one of 10 Republican senators who voted against one of the two impeachment charges.