I don't know about "none" but there's a degree of controversy over when large scale Germanic settlement began, as in whether it was in concert with existing late Roman society in the 4th century, or in the aftermath of the collapse of Roman society in the 5th.

Although even if you take the later view, given the record of barbarian attacks on Britain in the earlier centuries like the 3rd, and that such attacks probably took place piggybacking off of already established trade links with the continent, it's quite likely that Germanic languages were already spoken sporadically amongst traders or foederati.

Its just the matter of size and percentage (which I'm assuming is your real question) that's up for considerable debate. But if your bounds are simply if "any" germanic language was spoken before the 5th century, the answer is very likely "yes".