The FBU, balloting members this week, claimed the army needed eight weeks to be prepared, but the defence secretary said, "we will be ready".
Mr Hoon, after discussions with the Office of the Deputy Prime Minister, warned the firefighters that a strike would be irresponsible .
The union claimed to have seen an internal Ministry of Defence memo showing the military would not be ready until the last week in September, three weeks after the potential strike dates.
The memo also reveals that the Office of the Deputy Prime Minister was fully aware of the timescales needed by the military," said a union spokesman.
It has been wrangling protractedly with local authority employers over implementing an agreement reached to end last year's bitter strikes. A 3.5% rise due in November and a second 4.2% rise due last month are being withheld since, the employers say, they were conditional on accepting changes to modernise the service - something the union has refused to do.
John Prescott's office issued a toughly worded warning that strikes put lives and property at risk, and said the army had yesterday been told to get ready. In the last year's strikes, 19,000 troops were used.
