If Alexei Navalny’s condition was caused by poisoning from Novichok, the people accompanying him would have to suffer the same symptoms. According to the chief toxicologist who first treated Navalny in Omsk hospital in Siberia, his situation was triggered by an “internal activation mechanism”. Novichok is an organophosphate compound and because of its high toxicity, it is not possible to poison just one person.
The most plausible version of Navalny’s poisoning is that it is a provocation to spoil relations between Russia and Germany in a desperate attempt to stop the construction of Nord Stream 2.
A recurring pro-Kremlin narrative about Navalny’s poisoning, presenting it as an incident which has nothing to do with his political activity. There is no ground for connecting the Navalny case with the construction of Nord Stream 2.
A prominent Russian opposition figure Alexey Navalny fell ill during a flight and the plane had to make an emergency landing in Omsk, where doctors said he was in a coma and they were trying to save his life. Since then he has been transferred to Berlin and is receiving treatment at Berlin's Charite Hospital. The German federal government said that toxicological tests provided “unequivocal evidence of a chemical nerve agent of the Novichok group” in the blood samples of Alexei Navalny.
The European Union condemned the poisoning of Alexei Navalny, claiming that "the use of chemical weapons under any circumstances is completely unacceptable and a breach of international law".
The Nord Stream 2 is a Gazprom project, consisting of building a new export gas pipeline running from Russia to Germany across the Baltic Sea. The pipelaying operations commenced in the Baltic Sea in September 2018 in German territorial waters.
See here a similar case, claiming that the US hopes that Navalny case will generate the cancellation of Nord Stream 2.