President-elect Joe Biden’s plans for a major new economic relief package boosting stimulus payments to $2,000 ran into possibly fatal opposition from his own party Friday as Sen. Joe Manchin III (D-W.Va.) said he would “absolutely not” support a new round of checks.

Manchin, a moderate who will hold great sway in a Senate split 50-50 between Democrats and Republicans, made his views known even as the Biden team worked to develop a coronavirus relief package that would include new stimulus checks, extended unemployment benefits, and more.

Biden is also expected to push for additional funding for vaccine distribution, as well as money that will help states and cities, as part of his initial package, according to three people with knowledge of the matter, who spoke on the condition of anonymity ahead of a formal announcement.