RORY Stewart has said he expects to be branded a "traitor" for voting against a no-deal Brexit

The MP for Penrith and The Border, who rose to fame during the Tory leadership contest, said his political career will probably be damaged for up to a decade. 

It came as he launched a scathing attack on nationalism and insisted Britain's recent past meant it had never had to confront its darker side.

Mr Stewart made the comments during an interview with Guardian journalist Charlotte Higgins at the Edinburgh International Book Festival. 

He said: "In a way, what I'm about to do, which is to go back and vote against a no-deal Brexit, will mark me in the eyes of many of my colleagues and many party members as a traitor who's been trying to undermine the whole project. 

"And that will probably damage me for five or ten years."

Mr Stewart insisted the United Kingdom "represents complexity, compromise, trade-offs" and is "an argument against oversimplification".

He added: "In the end, nationalism is reductive. It always involves reducing the size of a country. It always involves pretending that there is a big, simple solution."

He continued: "The instinct has to be the opposite. That's why I'm against a no-deal Brexit. It's the same thing. No-deal is the same – no-deal is a negative."

Mr Stewart said the only way to stop the march of political nationalism "is to really dig into the moral outrage against nationalism in its worst forms". 

He said: "In Germany, people understand what's wrong with nationalism – they really, really understand it. 

"Even in France – even though nationalism is on the rise – basically most people in France get it; they get what's wrong with it.

"We live in a very strange country where, because of our experience in the Second World War, we never really had to think about what the negative sides of nationalism might be."

He continued: "We think it doesn't matter, talking about Bannockburn or William Wallace or [the Battle of] Crécy or Agincourt or Henry V. 

"We take it quite lightly because we never went through the experience of the Second World War – we never sense just how crazy this stuff is."

Elsewhere, Mr Stewart said he was "definitely thinking" about running for the Tory leadership again in future, but suggested he felt such a move might be pointless.

He said: "I'm 46 now, and I have to think about the next 25 years – how can I be most useful? What can I actually do for this country?

"And it may be that spending the next 15, 20 years of my life trying to be Prime Minister may not be the most useful contribution I can make."

The MP said politics is currently "defying all the rules of normal life", adding: "Somehow the idea of leadership has become fairy tales – the leader is the person who can produce the most absurd and extravagant fair tale."

He also painted a negative picture of politics in general, arguing it is a "very damaging, corrosive thing".

Mr Stewart said: "After nine, ten years in politics, your mind, your heart, your soul is actually eroded in a hundred ways that you can't quite begin to describe and imagine."

He added: "Unfortunately once you became Prime Minister, even if you were nice when you began, you would very quickly cease to be."