Deputy Prime Minister and Defence Minister Władysław Kosiniak-Kamysz said the bill, dubbed the "pre-war law," draws on lessons from the war in Ukraine.
The ministry had analysed legal changes made there, he noted.
"You can't transfer it one to one, but there are some inspirations and pointers," he added.
The existence of the bill was first reported by the Polish Rzeczpospolita daily.
Deputy Defence Minister Cezary Tomczyk told private broadcaster RMF FM the ministry had been working on it for several weeks and would present it publicly once internal consultations are complete.
"The sooner, the better," he said when asked when that would be.
According to Rzeczpospolita, the bill would allow earlier movement of troops, including allied forces, link Poland's defence response plan with NATO's system, and provide for infrastructure preparations.
It would also widen the range of bodies involved in standing duty and state defence command arrangements, set rules for civilian staff at command posts, and change rules on training and exercises.
President Karol Nawrocki's National Security Bureau (BBN) is awaiting the draft, according to the paper.
Deputy Defence Minister Paweł Zalewski said the agency had been informed.
Kosiniak-Kamysz told reporters on Friday he did not want to frighten anyone, but that a responsible government had a duty to be prepared for the worst scenarios and to inform the public.
He pointed to foreign missiles violating Polish airspace, drones flying near the border, sabotage, GPS jamming and cut undersea cables in the Baltic.
"When will we talk about this, if not now?" he said.
Separately, new military procedures on identifying and shooting down foreign aircraft and missiles took effect on 1 October, Tomczyk confirmed.
Until now, in peacetime, a pilot has generally had to make visual contact with an intruding object before it could be shot down, to avoid mistakenly hitting, for example, an allied or civilian aircraft with a technical fault.
Under the new "positive identification" approach, a combination of factors, such as a radar reading, entry into a restricted zone and information from Ukrainian allies that an object is a cruise missile, can be enough to justify an order to fire.
Kosiniak-Kamysz said the aim was to have a clear and readable "algorithm of conduct, a scenario for acting in extremely difficult conditions that demand a lightning-fast response."
"We have simplified this to the maximum, based on existing regulations," Kosiniak-Kamysz told the media.
(ał)
Source: PAP