Guard 1 (The Deadly Assassin)
From Tardis Wiki, the free Doctor Who reference
A guard was a member of the Chancellery Guard. When the Fourth Doctor arrived in the capitol and was being pursued by guards, he stopped at an elevator, which opened and revealed the guard. The guard held the Doctor at gunpoint before being shot and killed by the Decayed Master. (TV: The Deadly Assassin)
Behind the scenes
Pat Gorman clearly plays the guard again in part two, although Hilred said he was killed in part one.