Just keep trying. I got through eventually after some trouble last night.
After an unsuccessful attempt I later received an email asking me to click a link to confirm that I wanted to sign the petition.
I was then redirected back to the petition website. Even then it didn't accept the submission until I had confirmed a second time.
Maybe the website isn't used to having such volume in a short time frame. Unsure what sort of numbers usually sign petitions but I'd say this initiative is popular!
After an unsuccessful attempt I later received an email asking me to click a link to confirm that I wanted to sign the petition.
I was then redirected back to the petition website. Even then it didn't accept the submission until I had confirmed a second time.
Maybe the website isn't used to having such volume in a short time frame. Unsure what sort of numbers usually sign petitions but I'd say this initiative is popular!