Is this the new line to be used whenever a Labour politician is accused of wrongdoing?

First I reported the BBC reporting the Prime Minister's spokesman thus:

"It is an obvious statement that the prime minister would never mislead Parliament, clearly."

Now the BBC report Keith Best of the Immigration Advisory Service as saying that:

"And I would have thought it's incomprehensible or beyond doubt that a government minister would knowingly employ an illegal migrant."

Are we still expected to swallow the line that the members of this Labour government are still "purer than pure" so that any indiscretion must just be an honest mistake? I will not swallow that, will you?