Christian groups today rushed to brand the government's Autumn Statement "half-baked" and a "massive offensive" against poorer families.

Chancellor Phillip Hammond admitted Brexit had created a £122bn black hole in the government's first major economic announcement since the vote in June. Economic growth predictions were slashed, forcing the government to borrow to fill the void.

Hammond abandoned his predecessor's George Osborne's ambition to run a surplus by the end of this parliament in 2020 but insisted he would make the economy "resilient as we exit the EU and match-fit for the transition that will follow".

The key announcements were:

• Reducing the "taper rate" at which benefits are withdrawn when people start work
• Increasing the National Living Wage from £7.20 to £7.50 from April 2017
• Banning letting agents fees
• Cancelling the fuel duty increase for the seventh consecutive year
• Confirming a previous announcement that the personal allowance would rise to £12,500 by 2020
• Announcing the higher tax band would rise to £50,000 by 2020

But Matthew Reed, chief executive of the Children's Society, said the plans offer a "soggy bottom" and would not provide any comfort to millions affected by pre-existing cuts.

"These improvements are measly morsels next to the nearly £11bn of ongoing cuts announced last year which will cut support for struggling families in 2020," said Reed.

"It must go much further – by scrapping the benefits freeze and the two-child cap, and restoring the family element of Tax Credits and original work allowances to Universal Credit – if its promise to help the JAMs ['just about managing'] is going to stick."

A coalition of churches including Baptists Together, the Presbyterian Church of Scotland, the Methodist Church and the United Reform Church warned "big benefit cuts are coming".

Policy advisor Paul Morrison said the change in taper rate "is a drop in the ocean".

He warned that the freeze on benefit payments would mean a cut in reality once increased inflation was taken into account.

"Parts of the press have declared that the "war on welfare claimants is over" but in reality the next massive offensive is just about to begin," said Morrison.

"The result is those earning the least or not earning at all – the Not Even Managing – are hit harder and faster than was planned."