SINGAPORE - Unions in other countries are mainly concerned with pushing for wage increases, but here in Singapore the labour movement advocates raising wages sustainably.

That is why productivity is such a key focus, labour chief Lim Swee Say said on Friday.

"You will not find anywhere in the world where the labour movement is such a key advocate for productivity...but in Singapore we recognise that the wage increase can only be sustained if it's supported over the medium and long term through productivity gain," said Mr Lim, who is secretary-general of the National Trades Union Congress.

Speaking to reporters after viewing two projects to improve cleaners' workflow at a hawker centre and food court, Mr Lim said he is encouraged that more and more workers have benefited since the Progressive Wage Model was implemented in the cleaning sector. The model sets out a wage ladder and structured career path.

But, he cautioned: "If we are not able to acheive a breakthrough in the productivity ladder, the wage ladder and job ladder will be constrained."