Two British Muslim members of the House of Lords have arrived in Sudan to push for the release of a British teacher imprisoned for insulting religion.
Baroness Warsi and Lord Ahmed could help resolve the crisis
Gillian Gibbons, 54, from Liverpool, received 15 days in jail after children in class named a teddy bear Muhammad.
Lord Ahmed and Baroness Warsi are expected to see Mrs Gibbons soon. They are also due to meet Sudanese President Omar al-Bashir and the chief justice.
Mrs Gibbons has been moved to a secret location amid fears for her safety.
Crowds of protesters have marched in the capital Khartoum calling for a tougher sentence for Mrs Gibbons. Some have even demanded the death penalty.
Labour's Lord Ahmed and Conservative shadow minister Lady Warsi travelled to Khartoum on their own initiative after private negotiation with Sudanese officials.
His office told the BBC: "We have it from the top that Sudanese authorities will co-operate in relation to her release."
The BBC's Amber Henshaw reported from Khartoum that the peers were due to see Mrs Gibbons "shortly", although their meeting with the president had not been confirmed.
She said Mrs Gibbons was transferred to a secret location after mounting fears for her security.
The Foreign Office has made clear that the peers' visit is separate to its ongoing efforts to get Mrs Gibbons freed.
Sources close to the Sudanese government say there is far more chance of it making a deal with the peers than the British government.
BBC security correspondent Frank Gardner says the meeting could provide a way out of the diplomatic crisis.
He said the Muslim delegation is expecting to meet the president on Saturday and return to the UK by Monday, hopefully with Mrs Gibbons.
"Analysts believe it would suit the Sudanese government to be seen to be showing mercy in handing her over to a Muslim delegation, instead of appearing to 'give in' to their former colonial masters, the British government," Mr Gardner said.
Meanwhile, Mrs Gibbons' son has said his mother does not want the situation to spark "resentment" towards Muslims.
Crowds have marched in Khartoum demanding a tougher sentence
John Gibbons, 27, from Liverpool, said she was "holding up quite well".
He told The Associated Press on Friday: "One of the things my mum said today was that 'I don't want any resentment towards Muslim people'.
"She doesn't want people using her and her case as something to stoke up resentment towards anyone, towards Sudanese people, towards Muslim people or whatever.
"You know, that's not the type of person she is, that's not what she wants."
He added she was in good spirits and did not seem too distressed.
"She's holding up quite well. It was nice obviously to speak to her and hopefully we will be able to speak again," he said. "It's made me feel a hell of a lot better."
The Foreign Office said Mrs Gibbons had been visited again by consular staff on Friday and that she was "well", but it could not confirm where she was being held.
A spokeswoman said: "We are pursuing diplomatic contacts with the Sudanese government, we are continuing to do so and will throughout the weekend both in London and Khartoum.
"We are continuing to search for a swift resolution of this issue."
Some reports said protesters had called for her to be shot. Her lawyer said she was later moved for her own safety.
In September, Mrs Gibbons allowed her class of primary school pupils to name the teddy bear Muhammad as part of a study of animals and their habitats.
The court heard that she was arrested last Sunday after another member of staff at Unity High School complained to the Ministry of Education.