According to the book of Michael Swan Practical English Usage:
Be +likely is often followed by infinitive. (Probable cannot be used in this way).
- I am likely to be busy tomorrow.
- Are you likely to be staying in this evening.
- Do you think it is likely to rain?
- He is unlikely to agree.
It is not used as a preparatory subject in this structure.
- He's likely to succeed. (NOT It is likely for him to succeed.)
Could you please clarify about the last two line? I think we are not allowed to use this format:
'it is likely ... to ..'
'The Environment Agency has warned that it is likely to be an ongoing problem.'
As we know, 'It is likely to rain' is grammatically correct, but we used 'it' as a subject in above sentence. And it is the opposition of Michael Swan book.