I (British National) am looking to arrive in Khartoum at 01:00 from Istanbul and leave for Amman at 05:25.

Some of the posts talk about no visa being required if transiting within 6 hours. According to http://www.worldtravelguide.net/sudan/passport-visa

"Visas for Sudan are required by all nationals referred to in the chart above, except transit passengers continuing there journey from Sudan within 24 hours."

Can anyone say for sure whether I need to get a visa beforehand. The London Embassy offers a Transit Visa for 1-7 days stay but I have no idea how long it takes to get it.