Attempting to push to a newly created repo causes error at SSH layer

I've just created protostome/pchat. I am unable to push to it:

{{

{\\ $hg push -v "ssh://hg@bitbucket.org/protostome/pchat"\\ running ssh -C hg@bitbucket.org "hg -R protostome/pchat serve --stdio"\\ remote: Agent admitted failure to sign using the key.\\ remote: Permission denied (publickey).\\ abort: no suitable response from remote hg!\\ }}

}