Verb
put up or shut up (third-person singular simple present puts up or shuts up, present participle putting up or shutting up, simple past and past participle put up or shut up)
(idiomatic) To desist from saying something unless one is able to prove it; to act in a manner that makes further talk unnecessary.
The Conservative Party must make its choice. Every leader is leader only with the support of his party. That is true of me too. That is why I am no longer prepared to tolerate the present situation. In short, it is time to put up or shut up. John Major
If we don't get gun-control laws in this country, we are full of beans. To have the National Rifle Association rule the United States is pathetic. And I agree with Mayor Michael Bloomberg: It's time to put up or shut up about gun control for both parties. Harvey Weinstein