New Job Offer - what to do?

I currently work in technology lobbying earning 62,000 GBP (c.75,000 USD). I'm 26, and work for a global top 5 company in my field.

I have been offered a job at a technology management consultancy firm for 100,000 GBP (c.120,000 USD) doing business development/new business, as opposed to lobbying.

I have some experience in new business, but this probably takes me away from my career goal of becoming a 'Head of Public Affairs' at a major corporation. However, the money is very appealing with a young family.

How would you go about deciding what to do?