Ministers are likely to exercise caution in their response to the reports due to concerns over Russia’s reaction, as well as to ensure the move is not seen as being led by the UK.
In the Commons earlier, Healey said: “Ukraine’s action on the battlefield speaks for itself.”
Ukraine’s Defence Minister Rustem Umerov has also declined to confirm that his country has used the Storm Shadow missiles within Russian territory, but said it was “using all the means to defend our country”.
Matthew Miller, the US State Department’s spokesman, would also not comment on the use of the UK-supplied missile or whether the US was providing navigational assistance for their use.
When asked by the BBC if Ukraine was consulting with or informing the US about the use of missiles provided by the UK, Mr Miller said he would not “speak publicly to the use of another country’s weapons”.
President Volodymyr Zelensky has repeatedly called on Kyiv’s western allies to authorise the use of long-range missiles against targets inside Russia, saying it is the only way to bring about an end to the war.
Storm Shadow is considered an ideal weapon for penetrating hardened bunkers and ammunition stores, such as those used by Russia in its war against Ukraine.
The US and UK had previously not given permission, with suggestions this was related to not wanting to escalate the war.