Nepal was asked to dissolve his alliance and make way for a Maoist-led national government as proof that the army was not running the country.
The Maoists have been making that allegation since they tried to sack the army chief, Gen Rookmangud Katawal, but were frustrated by President Ram Baran Yadav who reinstated the general.
As their government fell due to the feud, the Maoists are blaming the president and will boycott his public programmes during their month-long protests.
While Prachanda's deputy and former finance minister Baburam Bhattarai is leading the protests, the supremo himself is off to Britain.
The trip comes even as the Maoists demanded the resignation of Health Minister Uma Kant Chaudhary, who had been on another trip to Germany while a raging diarrhoea epidemic killed nearly 250 people and affected thousands.