The head of the European Commission sparked fury after he said punishing Britain over leaving the bloc will make EU states realise “it’s not worth leaving”.
The business tycoon and co-chair of Leave Means Leave said Mr Juncker’s outburst was “inappropriate” before negotiations have formally begun.
Mr Tice said: “For the President of the EU Commission to make these disparaging comments before negotiations have started is completely inappropriate as well as being illegal according to the wording of Article 50.
“It seems clear that he is determined to pursue a spiteful campaign against Britain, which will impact negatively on the citizens of the EU he claims to represent.
“No deal is better than a bad deal and if the EU is adamant about offering us such a bad deal, the Prime Minister should walk away at the earliest opportunity.
“Adopting World Trade Organisation rules is a perfectly acceptable way for Britain to proceed, it is what we do with most of the rest of the world anyway.
“We can only truly benefit from Brexit when we leave the EU and if they have no intention of negotiating, this should happen sooner rather than later.”
Mr Juncker warned that Britain may have to abandon its hopes of a trade deal if it rejects the terms offered by the EU – which are widely expected to include a “divorce bill” of as much as £50billion.
The UK will have “the choice to eat what’s on the table or not come to the table at all”, Mr Juncker told German newspaper Bild am Sonntag.
Mr Juncker claimed Brexit would ensure the survival of the crumbling bloc.
He said: “Britain’s example will make everyone realise that it’s not worth leaving.
“On the contrary, the remaining member states will fall in love with each other again and renew their vows with the European Union.
“Half memberships and cherry-picking aren’t possible. In Europe you eat what’s on the table or you don’t sit at the table.”
In a veiled threat, Downing Street responded to Mr Juncker’s claims.
Mrs May’s spokesman said: “We have said many times we are at the start of negotiations and let’s see how it unfolds.”
The Prime Minister has vowed to “negotiate hard” for the best possible deal for Britain as it leaves the EU.
Mrs May’s letter officially notifying the European Council of the UK’s intention to quit under Article 50 of the EU treaties will set in motion a two-year negotiation process expected to lead to Britain leaving the EU on March 29 2019.
European Council president Donald Tusk confirmed that he will present draft Brexit guidelines to the remaining 27 member states within 48 hours of notification.
March 20th, 2017: Express