Presumably Corbyn for once has found an urgent engagement and hasn't managed to attend this protest
He probably did what Livingstone did when he rocked up, in 2008, despite being snubbed by Chavez, Livingstone claims he visited a Socialist paradises of social housing, but neglected to actually name the places, or give any directions to get there.
Livingstone's fake paradise The Handstand (thehandstand.org) 2008
"Caracas showed visibly the problems the country faces and progress made in recent years. In west central districts the houses of the old elite and upper-middle class are better than the most upmarket London suburb.
They are surrounded by several million people living in poverty in "barrios" – rough-built slums perched on the side of mountains without basic facilities. These areas were not even marked on the maps under previous administrations!
This is the product of a system where tens of billions of dollars of oil wealth each year were sent abroad to serve this elite without addressing the most elementary questions of quality of life of the majority of people.
That has changed. A trip to one of many new community facilities showed how millions of people have been given access to a new free healthcare system, including dentistry. Illiteracy has been eliminated to Unesco standards. Further education is being rapidly expanded."