on the grounds that

English as a Second Language English Vocabulary, Grammar and Idioms
1

what does this prease mean “on the ground that…”?

2

dependent on the context , it most likely means “on the ‘condition’, or ‘basis’ that…”
hope that helps.

3

Hi Biglittleboy,

I would say: On the grounds that … suggesting on the basis that …Possibly the singular use of the word tends towards the literal whereas the plural suggests more the figurative use.

Alan