Shadow Foreign Secretary Douglas Alexander said:
On the same day that top British business leaders fired a warning shot across the bows of the Prime Minister, a senior White House official has also signalled concerns about the possibility of Britain leaving the EU.
There is today a real risk of Britain sleepwalking towards exit because of a Prime Minister motivated more by the need for party unity than by the interests of the country.
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The MEP predicted many more could withdraw support for party leader Paul Nuttall as he hit out at the newly unveiled integration policies.
Interesting weather today - the sunshine as strong as late summer, but the air as cold as midwinter.
The President's daughter was met with audible groans as she talked about how her father has been "supporting families".