A shake-up of Welsh language education cleared the first hurdle in the Senedd despite concerns about staff shortages, teachers’ workloads and the cost to schools.

Senedd members unanimously agreed the general principles of the Welsh language bill, which was part of the now-collapsed co-operation deal between ministers and Plaid Cymru.

Mark Drakeford told the Senedd the reforms aim to improve how Welsh is taught, ensuring all pupils become confident Welsh speakers by the end of compulsory school age.

The finance and Welsh language secretary said: “The majority of children in Wales receive their education through the medium of English.

“It has been mandatory for them to learn Welsh for decades now.

“But we know that we haven't succeeded in providing the same quality of experiences to them.”

The bill, which would cost an estimated £103.2m in the years to 2034/35, would set a 10 per cent minimum level for the amount of Welsh provision in primarily English-language schools.

It would also put targets including a million Welsh speakers by 2050 on a legal footing; embed a standard way to describe language ability based on the CEFR; establish new categories of school; create a chain of accountability with duties on schools, councils and ministers; and set up a National Welsh Language Learning Institute.

Leading a debate on 14 January, Prof Drakeford said: “If the bill is to succeed then we must ensure there is capacity within the education system to implement it.”

He pointed to the education secretary’s announcement of a strategic workforce plan, which will include the teaching of Welsh and teaching through the medium of Welsh.

Prof Drakeford committed to bringing forward amendments to address workforce concerns as the bill moves through the Senedd’s four-stage scrutiny process.

Buffy Williams, chair of the education committee, said: “It is rare for a government target … to capture a wider imagination but a million Welsh speakers by 2050 has.

“Yet, the last census result shows a decrease in the number of people saying they’re Welsh speakers.

“It is clear action is needed to put this decline into reverse.

“The bill, we believe, is an important mechanism to support delivery of this target.”

Ms Williams warned the biggest barrier is having a workforce with the right skills, saying: “This is not going to be easy. We know there are currently shortages across Wales.”

Sam Kurtz, the Tories’ shadow Welsh language secretary, welcomed the ambition to increase the number of Welsh speakers.

But he said: “Key challenges remain, particularly in terms of workforce capacity,” warning of the financial implications for “already stretched” schools and councils.

Plaid Cymru’s Cefin Campbell, shadow education secretary, said targets to expand Welsh-medium education have been missed for more than 20 years.

Warning minority languages are “hugely fragile” around the world, Lee Waters MS described the bill as a uniquely ambitious and important step.

He said pupils in primarily English-medium schools are currently “shortchanged”, with a low chance of them leaving school being able to hold a meaningful conversation in Welsh.