Q: What can I do if my co-author submitted new data post-review without my consent?

I am the first author of a manuscript that was recently "accepted in principle".The submission, peer review, and revisions of this manuscript happened after I left the laboratory of the corresponding author where I was a postdoc. I was actively involved in the revisions. Following peer review and revisions, the corresponding author wanted to include new data which I did not approve of because I felt it was extraneous and confounding. In spite of my clear objection, he submitted this data without my consent. After multiple unsuccessful attempts at trying to resolve the issue with the corresponding author, I contacted the journal editor. She sent a rather timid email to the corresponding author saying that it was okay to add in data after peer review since manuscripts are not "frozen" after they are accepted in principle. She said she was willing to include this data if it strengthened the manuscript and asked the lead author to contact all co-authors and obtain their consent before the final submission.The lead author is still refusing to change his decision. He told me that he will easily get all other co-authors to consent to this. In which case, he said that it will appear that I am trying to suppress useful data. I feel bullied here since I cannot match up to his seniority and his relations with the co-authors. He has so far not provided any clear scientific reason for including this data. Any guesses on what decision the journal will take if both I and the corresponding author continue to disagree, and I am the only one not giving consent?