Theresa May faced a serious blow to her authority today, when a semi-secret court accepted Abu Qatada's arguments against his deportation to Jordan.

The home secretary will be relieved the news comes on the same day as the crisis at the BBC because the ruling directly contradicts several of her assurances over the affair.

It is particularly damaging because it was May's decision to pursue the case through the British courts rather than appeal the original European court of human rights ruling.

"This is an extremely serious and worrying judgement which completely contradicts Theresa May's repeated assurances that she had the right legal strategy to get Abu Qatada deported to Jordan," shadow home secretary Yvette Cooper said.

"The home secretary needs to explain urgently why she refused to appeal the European court judgement that has now led to today's decision. And she needs to explain what assurances she did get from Jordan and why they have failed."

The ruling by judges at a Special Immigration Appeals Commission means Qatada will be released from jail tomorrow. He will be under curfew for 16 hours a day.

The radical cleric is facing a re-trial in Jordan for allegations around attacks against western targets in 1998 and 1999.