in the van
in the van of (something)
At the forefront of something. The lieutenant who was in the van of the assault, leading a small party of machine-gunners to clear a path for the rest of the infantry. The senator had been in the van of the movement to equalize pay for all citizens since the late 1960s.
in the ˈvan(British English, formal) at the front or in the leading position: The eight warships in the van opened fire on the advancing fleet.
See also: van