The redundancies come on top of 240 sackings announced at the factory last November.
Production of children's shoes at four other factories in Somerset, Devon and Avon will not be affected by the closure at Radstock, which will cease all operations before the end of this year.
A spokesman for Clark said: "For some time now, demand in the UK for children's shoes has been declining, and sales in the market as a whole have fallen by 20 per cent in the last five years."
This problem with the children's shoes market was strongly highlighted during the bitter family feud over the proposed but unsuccessful £165m take-over bid by Berisford in 1993 for the 167-year-old shoe company based in Street, Somerset.
"While the group has seen significant growth in overseas business recently, this has been principally in adults' shoes," the spokesman added yesterday.
Since the first round of job cuts was announced, the company has tried to see if new or alternative products could be made competitively at Radstock.
However, the spokesman said: "In the meantime, more pessimistic forecast of demand for the factory's products has been confirmed, which, allied to current over-stocking, indicates a production requirement far short of economic capacity."
He added: "There is no indication that the situation can be improved significantly in the future."
The company hopes to offer a "limited" number of job transfers to staff at Radstock to the other factories at Bath, Illminster, Shepton Mallett and Exmouth.Reuse content