Mr Tugendhat, who is chair of the Foreign Affairs Committee, will be at the forefront of dealings with the EU when Britain officially leaves the Union.
The House of Commons returned from its summer break yesterday [Tuesday] but has only four days to sit before the five-week suspension begins.
MPs will then have from October 14 until the Brexit deadline of October 31 to debate the issue. Usually Parliament is suspended for three weeks at this time of year for party conference season.
Mr Tugendhat said Boris Johnson’s move to suspend Parliament in the run-up to Brexit was ‘deliberately confrontational but not unconstitutional’.
He told the Times: “When the issues in question are so important it goes against the concept of Parliamentary sovereignty – a key reason for leaving in 2016 [referendum] – to reduce the time which Parliament sits and debate matters of such importance.”
He described it as a ‘massive dead cat on the table’, referring to a strategy where something dramatic and shocking is said or done in order to divert attention away from another damaging issue.
It’s a phrase Mr Johnson employs himself, as a tactic he admired in the work of his former mayoral campaign manager, Tory spin doctor Lynton Crosby.
Mr Tugendhat said: “Despite the smoke, there’s not much fire. [Party] Conference Recess was there anyway, this extends it by a few days. So why do it?
“There are a few possibilities but the most likely are: This is a massive dead cat on the table to stop people talking about how to avoid no deal and instead talk about process.
“This makes it clear to the EU there’s no way past October 31. This makes it easier to pass a deal. When Parliament comes back, after the EU Council on October 17, there will be one item on the agenda and, unlike last time, no possible extension. The choice will be deal or no deal, with no way out for Labour, Lib Dems, etc.
“This isn’t endorsement, it’s observation. I’m not [backing Boris]. I’m describing his tactics. He’s setting a dangerous precedent.”
He went on to describe the two forces at work, direct democracy – such as the EU referendum, when policies are decided by the public – and representative democracy, when the elected representatives make the decisions.
“The problem is that there are two competing democracies in the UK today,” said Mr Tugendhat. “They can’t both win and the legitimacy of each is being challenged.
“The issue is so substantial it affects all others, and the question on the delivery of the referendum has become a question on the legitimacy of representative democracy or direct democracy.”