Alok Sharma spoke after reports Number 10 was trying to sideline First Minister Nicola Sturgeon.
Reports have suggested the climate conference could be held virtually amid the coronavirus pandemic.
Media reports on Wednesday suggested that the Glasgow summit this year may be pushed back or scaled down.
Alok Sharma was tested after appearing visibly unwell during a statement in the Commons.
The Prime Minister could be asked to self-quarantine again if business secretary Alok Sharma tests positive.
The STUC has written to the UK Government accusing it of 'mixed messages and confusing briefings'.