Leaving Plusnet - Cease on Line?

[#1]

I've decided to jump ship and my contract renews in June - so I've asked my new supplier to start their service from then.

They have asked me to tell Plusnet to "make your current supplier aware not to put a cease on the line" - how do I do that? Why would Plusnet 'cease my line' before my contract ends?

[#2]

@millimole 

Your best bet is to tell Plusnet nothing and let the new ISP take over your working line. What you must not do is tell Plusnet that you are cancelling your service on a specific date as this will result in the line being ceased on that day. The new ISP will then have to restart the line, causing a break in service of many days or longer.

[#3]

Thank you - you have perhaps confirmed my suspicions - that it's better to do nothing, rather than something! 
I shall sit on my hands and deal with issues as they arise (or hopefully don't)!