Work to transform the old St Ilan School site into a new Welsh school has been given a £3 million boost from the Welsh Government.
Education Minister Leighton Andrews has confirmed the project will receive the extra funding as part of an extra £35.7m being allocated to school building projects.
Last year, the Welsh Government initially confirmed £1.75m in funding for the scheme.
Caerphilly AM Jeff Cuthbert, who is also the Deputy Minister for Skills in the Welsh Government, has welcomed the funding.
He said: “I’m very pleased by the funding that has been secured for the new Welsh-medium school at the old St Ilan site, which will complement the extremely popular Ysgol Gyfun Cwm Rhymni.
“Cwm Rhymni has an excellent reputation and rightly so. However, it does need extra capacity and this new school in Caerphilly will help to absorb that and provide a first-class Welsh-medium education to local schoolchildren in the area.
“Despite the intense financial pressures that are being felt by the Welsh Government and the local authority, I’m pleased that money has been found for this important project so that work can get started on the new premises as soon as possible.”
Caerphilly County Borough Council is currently developing the closed St Ilan School site, off Pontygwindy Road, Caerphilly, into a new Welsh language school for pupils aged between three and 16. Some post-16 classes will also be taught on the new campus.
The county borough currently only has one Welsh medium secondary school – Ysgol Gyfun Cwm Rhymni in Fleur de Lys.
Forecasts have shown there will be an overcapacity of almost 1,000 pupils by 2021.
In January last year year, councillors voted to spend £3.5m to begin work on the first phase of the project. Year 7 pupils living in the Caerphilly basin will start at the new school in September 2013.
The new Welsh school will create an additional 900 secondary school places with YGG Caerffili also moving to the new site.
Permission has also been granted for a four court sports hall and changing facilities on the site as part of the development programme.