The three main political groups that backed Viktor Yushchenko's presidential bid in the Orange revolution of 2004 have agreed to end months of wrangling and form a coalition that will bring the fiery Yulia Tymoshenko back into government as prime minister.

The coalition agreement, due to be signed tomorrow after last-minute details are worked out, is seen as a big concession on the part of Mr Yushchenko, who fired Ms Tymoshenko in September after a seven-month term as prime minister marked by cabinet infighting.