What the Soviets did is irrelevant to the discussion, as we're merely talking about the legitimacy of the Communist government in legal theory.
It has everything to do with it because it was the Soviets who installed the Polish Communist Govt which is one of the key reasons behind why the Polish Communist Govt is illegitimate and unlawful.
You're mixing up constitutional theory and practice.
That's an interesting opinion. Do elaborate so I can learn from my mistakes...
but in terms of strict legality, yes, it was.
You could so easily vindicate your position by, once again, specifying which piece of legislation/Consitution (and the particular section, article etc) is authority for the proposition the the Communist Govt was 'legal'. Had you based your proposal on such foundations, you would have already provided us with such authorities, but you haven't, despite my request, which from previous experience really means your suggestions are baseless and wrong.
One cannot postulate a 'legal' submission without reference to the law or case authority to which it relates. Merely saying something was
done in accordance with the law
is not enough. It will be asked, as I have done, 'which law'? You seem to be saying 'the Constitution', but which Article of the Constitution?
The Lublin Government was the only one that could present a claim in 1945 based on the universally understood principles of sovereignty, which is why it was recognised by the West.
Please particularise the purported 'claim' and let us know how it accorded with this supposed universally understood principle of sovereignty. It must have been a principle promulgated and universally understood by the Soviets alone however, because I'm unaware of any principle or otherwise in respect of the legal and factual matters concerning sovereignty that say it's okay to occupy a country then install a puppet regime whose raison d'etre is to slavishly follow the said occupier's political and social mantra.
Poles and Germans walked a very long way together; they share a lot of their history. That's what they owe each other.
Please, don't be ridiculous. We all appreciate your favouring of your German heritage over your Polish one, but what historical common path of mutual harmony did Poles and Germans as nations walk together?