Ann Widdecombe has said she is "tired of hearing nonsense" about the loss of young people's rights to travel and work in Europe in the wake of Brexit.
The Brexit Party MEP was on fiery form on the final day of the UK's membership of the EU ahead of making a final "farewell march" from the parliament building to the Eurostar.
Speaking to the PA news agency, she said: "I have a mixture of feeling very, very jubilant and full of celebration but also profound relief because there was a time when I wondered if this day was ever going to come.
"Indeed it was at that point that I joined the Brexit Party to try and help to make it come."
Ms Widdecombe will be leading the Brexit Party's march after leader Nigel Farage left Brussels for the last time as an MEP on Wednesday evening following the final vote on the Withdrawal Agreement.
She said she would be joining the rest of the party in Parliament Square for the stroke of 11pm on Friday evening.
"And that's it. That is the moment when Brexit has been Brexited."
The former shadow home secretary is confident Brexit will benefit young people, saying: "It's all benefit.
"It's going to bring us the ability to control our own laws, the ability to control our own trade deals and the resulting prosperity and freedom and what I hope will be the return of common sense in regulation – all that is going to benefit everybody.
"I am tired of hearing this nonsense being talked that young people are going to be deprived of their rights to travel and to study in other countries.
"I'm old enough to remember the days before we joined – we travelled, we studied, we lived, we worked in each other's countries all the time and that's how it will be again."
When asked if the Brexit Party would take any responsibility if Brexit had a negative impact on the economy, she said: "The Brexit Party has freed Britain, what Britain does from now on is down to the Government – we are not the Government but we have made this possible.
"But already people are saying, 'supposing it all goes wrong?' Well, supposing it all goes right. Will people then apologise to the Brexit Party? I doubt it."
She said the Brexit Party would have to continue as a political entity for at least the next year.
"The negotiations are still going on and we need to make sure Boris doesn't get away with anything, that if he's giving stuff away, that the public know that.
"That is absolutely crucial. We've got to hold the Government to account in as much as we can for the next year, after that, who knows?"
Ms Widdecombe was unsympathetic towards the outpouring of grief from Remain supporters.
"One side had to lose in that referendum, would they have cared if we were sad, would they have cared if we had lost? The answer is no."
She added: "I would have been very sad if we had lost. But that is democracy, that is what it means. Somebody wins, somebody loses."
When asked whether the Withdrawal Agreement is what she had envisaged, she said: "I had rather thought it would be a much more hard-edged version, whereby we left on World Trade Organisation terms and started afresh from there.
"I wish Boris well as long as that negotiation doesn't give anything away because there's no need to – the EU is terrified we are going to be a competitor on its doorstep.
"That's what we've got to be and we can't agree that we have a level playing field."
"We've got to be pretty tough about this one."
The UK will leave the EU at 11pm this evening.