Write a function that, given a list of phone numbers, transforms them so they all start with a specified phone country code, preceded by the + sign. Any whitespaces from a phone number should also be removed. The following is a list of input and output examples:

07555 123456    => +447555123456
07555123456     => +447555123456
+44 7555 123456 => +447555123456
44 7555 123456  => +447555123456
7555 123456     => +447555123456