a drowning man catches at a straw
a drowning man will clutch at a straw

The majority caught at it as a drowning man catches at a straw.

Being in that condition in which a drowning man catches at a straw, our bore sent for Jilkins.

I know what you must think of me, how even you, my son, must despise me, but as a drowning man catches at a straw, I sent for you, hoping that you would in mercy pity me and help me."