President Yahya Khan of Pakistan to-day [New Delhi, Oct. 12] promised his people a new Central Government by the beginning of the new year, but gave no indication about its likely composition and character. In a 40-minute broadcast over Radio Pakistan, he said the constitution he planned to promulgate would be published by December 20 and the reconstituted National Assembly would be called into session on December 27. He said, “to accelerate the process of transfer of power the Central Government will be formed soon after the inaugural session of the National Assembly.” Gen. Yahya Khan sought to preempt criticism of his proposals by calling upon political leaders to take note of the alleged threat to Pakistan’s integrity from India and declaring that “on no account should the people’s attention be diverted from the basic issues of defence of the country and restoration of democracy.” He prefaced his constitutional proposals with a tirade against India, which, he alleged, had moved forward army formations and air force units to positions close to Pakistan’s borders. He claimed that there existed a “serious possibility of aggression by India against Pakistan.”