The Marshall Plan was an American financial initiative to rebuild western Europe after devastation of the war.
Britain was the biggest beneficiary, receiving around a quarter of what in modern terms, amounted to around $100 billion.
Speaking to Talk Radio’s Alexis Conran on Sunday, Kawczynski said he stood by the tweet despite its inaccuracy.
Conran said: “I need to figure out whether you are someone who can be trusted as giving answers and the truth is Mr Kawczynski, is that you have got this completely wrong and it has been pointed out to on Twitter by many, many people.”
He then asked the MP to look up the Marshall Plan to check the figures.
Kawczynski said: ”I have been asked here to talk about Article 50, if you want to speak about Article 50 then fine, if you don’t then we’ll call it a day.”
Conran said: “What does that say about you Mr Kawczynski, is someone is pointing out an inconsistency in your tweet?”
Kawczynski then hung up.