chinese visa - still valid in my british passport but I have second british passport issued -

I am a british citizen. I am almost out of blank pages in my passport. i have a second british passport that was just issued with blank pages. my original passport has on in it that expires on march 28th. I may not have enough blank space for entry/departure stamps for my trip next week in my original passport. If i am out of space for stamping in my original passport, may I use the second passport and refer to the one in the original passport for stamping?