Buckingham' s MP voted against government plans to toughen up Covid restrictions last night, Tuesday.
Despite the rebellion, the vaccine certificates measure was passed by 369 votes to 126.
As of today, adults in England will have to show a Covid pass to enter nightclubs, big sports matches and other large events.
Speaking before last night's vote, Greg Smith said: “I simply do not see the evidence to further restrict freedoms and liberties in the United Kingdom, especially given the absolute threat to the economy, mental health and ensuring the NHS is able to get the care and treatment needed to people with urgent conditions such as cancer and heart disease.
"Restrictions are not harm free, they cause significant harms in themselves.
“i have long opposed vaccine passports, which are divisive and discriminatory.
"They do not stop the spread of Covid and serve no medical purpose.
"This is obvious when you look at countries that have had health passes for some time, including Israel and locally Scotland and Wales.”