Minister of State for the Armed Forces of the United Kingdom, James Heappey, issued a letter to Tobias Ellwood, Chair of the Defence Select Committee, in which he "offered insights" into russia’s heavy bomber fleet, in particular. This is reported by the UK Defense Journal.
The minister says the russian strategic aviation fleet consists of about 80 aircraft, mostly Tu-95MS and Tu-22M3. James Heappey also notes that russians have "approximately 10" each of Tu-160 and MiG-31K aircraft and that they bear plans to "build new and modernize existing TU-160 BLACKJACK (NATO reporting name – ed.) airframes."
Read more: Satellite Shows why russians Barely Use Tu-160 Bombers for Attacks on Ukraine

The official doesn't rule out that russians might have significant progress in developing their PAK-DA strategic stealth bomber, though he mentioned sanctions and any economic problems due to the ongoing war in Ukraine cause delays in the implementation of such projects.
The data provided in this letter is important, for one thing, because it gives reasons for the statement that russia actually has 1.5 times fewer strategic bombers of the types Tu-22M3 and Tu-95MS than previously assessed.
According to the reference data, it was suggested that the strategic fleet of the russian "aerospace forces" comprises 60 Tu-22M3s and 60 more Tu-95MSs, i.e. 120 aircraft of the said types. However, now the official at the British defense ministry says the real fleet has only 80 aircraft, without specifying their operational condition.
As for the estimate of "approximately 10" for the Tu-160 and MiG-31K, it looks relatively close to the earlier assessments of about 16 Tu-160 and Tu-160M combined and 10 to 12 MiG-31K. James Heappey concludes that there are still a number of bomber aircraft at constant readiness across russia and even the active deployment of some for the war in Ukraine is "highly unlikely" to significantly impact russia’s nuclear readiness.
Nonetheless, this recorded decline of the russian heavy bomber fleet means quite a lot for Ukraine since it shows russia has only this many aircraft to engage in the war while it still must have enough bombers to maintain the proper level of response capabilities.
Earlier Defense Express also explained why russians barely use their Tu-160 bombers for missile attacks on Ukraine based on satellite imagery analysis.
Read more: The UK Defense Intelligence: russian Aviation Aims to Suppress Ukrainian Counteroffensive