This question already has an answer here:
I've worked for my current company for 9 months and feel that I have been underpaid. Another company has offered me a position with a salary of roughly double what my current company pays (technically it is 1.5x my current salary with a retention bonus of 0.5 my current annual salary payable after two years). I responded that I would need some time before I could leave my current company but that I could engage with the new company as a consultant in the mean time.
A few weeks ago I gave them an update that I thought it would be possible for me to join them in another 6 weeks.
Since this however (in the last few days) my current employer has offered me a raise - while not quite up to the levels of the other company it also comes with equity and I understand that as a startup they are limited in what they can pay.
I am also concerned that I may be seen as a "job hopper" if I leave my current employer so soon.
How can I communicate to the manager of the new company that I can't join them? Would it be better to propose further delaying my start date?