Currently, lastminute.com do not track affiliates and other channels differently. For this reason you will find the phone number on the page for affiliate traffic and any other traffic. This is certainly on the radar with lastminute, but at this time it will remain up there. Although not ideal, for lastminute.com's core demographic there is not a great amount of phone traffic compared to online. The leakage should be minimal.
lastminute.com chooses to display adverts of other merchants. As with the above, things would not display differently for various channels.
Finally, we do have an offer and voucher feed which can satisfy your requirements. Right now we push it manually, but in the coming weeks it will be automated. Drop me a line and we can get you sorted.