In response to the protests regarding the Belarusian presidential election, Lukashenko in early September pondered the possibility of a referendum on Belarus joining the Russian Federation.
Suppose the referendum takes place. If, according to the official end result (whether obtained in a free and fair way or not), the majority is against the accession, then presumably nothing would change, and it is likely not the result he is aiming for.
If, however, the result is in favor of joining Russia, it is unlikely that Vladimir Putin will then relinquish his post and appoint Lukashenko as his successor. Lukashenko would, in the best (for him) scenario go from being head of a sovereign state to the head of a federal subject of Russia—effectively he would relinquish power.
So what would he gain from a referendum? The only benefit I see is this: in a sovereign Belarus, there is a real chance that the protesters eventually overthrow him and he ends up facing criminal charges by a Sviatlana Tsikhanouskaya led new government led by his opponents. On the other hand, Russia recognizes him as the legitimately elected president of Belarus, and under Russian law, even if retroactively applied to Belarus, he likely has not committed any crime. Furthermore, if Belarus becomes part of Russia, he might be able to count on Russian support against any further protests.
Therefore, is the proposed referendum essentially a concession by Lukashenko that he knows he eventually cannot win this fight, and is just trying to save his behind? Or could there be other motives behind it?