British farming minister George Eustice said on Thursday he had resigned from government over Prime Minister Theresa May's decision to offer parliament a possible vote on delaying Brexit.
With just over a month until Britain is due to leave the European Union on March 29, May is still seeking changes to her Brexit deal in order to win the backing of parliament.
Under pressure from pro-EU ministers, earlier this week May promised lawmakers would get a say over whether to seek an extension to the Article 50 exit negotiation period if her Brexit deal and a 'no deal' were rejected next month.
"I have decided to resign from the government following the decision this week to allow the postponement of our exit from the EU," Eustice, who was minister for agriculture, fisheries and food, said in a letter to May.
Eustice, who said he would vote for May's deal when she brings it back to parliament, warned the terms of any extension would be dictated by the EU in a "final humiliation of our country".
"We cannot negotiate a successful Brexit unless we are prepared to walk through the door. We must therefore have the courage, if necessary, to reclaim our freedom first and talk afterwards," he said.
"We must be ready to face down the European Union here and now."