* No Borders activists block both exits of Europe's largest immigration prison using heavy concrete blocks and a scaffolding tripod

* Dozens of migrants held at the prison were due to be deported to Ghana on a specially chartered flight at midnight

Anti-deportation campaigners are blockading both exits of Harmondsworth and Colnbrook detention centres, near Heathrow airport, in a bid to stop the forcible deportation of dozens of Ghanaian migrants held at Harmondsworth. A specially chartered flight carrying up to 50 deportees is scheduled to leave to Ghana from an undisclosed airport at ten minutes past midnight tonight.

Eleven activists from the No Borders network have locked their arms together inside heavy-weight concrete blocks, preventing the coaches carrying the deportees from leaving the detention centre. Another protester is suspending herself from a 10ft tripod made of scaffolding poles. The blockaders, joined by at least twenty protesters holding banners and chanting anti-deportation slogans, have vowed to remain in place until the flight is cancelled.

This is the second time there has been a mass deportation flight to Ghana from the UK. The first was in November last year. Charter flights are being used increasingly by European governments to deport more and more unwanted migrants to a growing list of countries, with an average of one flight a week from the UK alone.

The action coincides with a week-long 'convergence' of No Borders activists from across Europe at Goldsmiths college, south London. The event's callout had called upon supporters to "take action against various aspects of the border regime in London and the surrounding areas."

One of the blockaders, Dave Leighton, 34, said: "This flight has to be stopped. Everyone, not just a privileged few, should enjoy the freedom to move and stay wherever they want or need, regardless of their nationality or bank balance. Forcible deportations reinforce a screwed-up system whereby the rich and powerful use borders as a convenient tool to divide and distract ordinary people from the real causes of inequality."

Another protester, Yvonne Mason, 26, added: "My friend will be on that flight. He suffers from chronic injuries following his violent arrest during an immigration raid last year. He has been locked up at Harmondsworth for almost a year without access to proper medical treatment. He should be provided with care and support, not be deported against his will."