Control of scale in warewash applications

A cleaning composition comprising:

• 0.5 to 12 wt % of a polymer comprising polymerized units of
• (i) 50 to 95 wt % of an ethylenically unsaturated carboxylic acid monomer or salt thereof,
• (ii) 5 to 50 wt % of an ethylenically unsaturated sulfonic acid monomer or salt thereof, and
• (iii) 0 to 22 wt % of one or more further monomers or salt thereof, the polymer having a Mw from 10,000 to 20,000;
• 1 to 10 wt % of a water soluble silicate having a water solubility of ≧10 g/100 mL at 25° C.;
• 20 to 80 wt % of an alkaline source;
• and
• 0.5 to 15 wt % of a surfactant;
• wherein the weight ratio of the polymer to the water soluble silicate is from 2:1 to 1.2:1.