Can my child enter UK with expired passport?

[bellac]

Thanks for taking the time to read. I am in desperate need of help and advice. I have not been able to reach the consulate in London.

My daughter now 5 years old and I have been living in the UK since 2012. We live near London. We are both Italian/US Citizens. I have both passports, my daughter just has her Italian which expired 5 months ago.

After moving here I had to register with AIRE. They registered myself, but there have been many issues registering my daughter. From what I hear recently she finally is register with AIRE in London, but it hasn't yet been noted in our town in Italy. I am unable to apply for her Italian ID card through the post because she needs to be fully registered with AIRE. Also, because she is not registered, our town in Italy believes she is still in the US and registered in Miami. In order to renew her passport I would have to go to Miami. The only option that it seems is for us to travel to our small town in Italy and complain in person and hopefully leave with her ID, but that may not even be possible.

It has really been a mess, and I have all emails/letters to prove it.

We are both traveling to Italy to visit family next month in April. I am unsure if she would be denied re-entry into the UK with her expired passport. I know she can travel to Italy with it and a few other countries since she is a child and less than 1 year expired. Could someone please explain the immigration laws getting back into the UK?

My passport, papers etc. are all perfect, how can they deny my child?

If I do decide to travel, what letters/documents should I bring with me? I was thinking of maybe asking the headteacher at her school to write a letter stating that she has been a student there since 2012 and is active, that we live here etc.

Also, shall I make a trip to the Italian Embassy in London to discuss this? The consulate is not helping whatsoever, neither is the one in Miami or my town in Italy.

Thanks for any help in advance.