I am writing to you to tender my resignation from membership of the Conservative Party. I was required to become a member in order to take up the post of Police and Crime Commissioner (PCC) for Devon and Cornwall.

Three reasons drive my decision: first, I no longer wish to make this level of commitment to party politics. Second – and why I am advancing this resignation – I am deeply disappointed in the Government’s inaction in support of forthcoming PCC elections. Thirdly, while I will remain a Conservative Party voter I have experienced tensions with the party in my role as police commissioner and want to make them a matter of record so as to inform others.

As I write, PCC elections are two weeks away. PCCs have been a flagship programme for the Government and in the Home Secretary’s own words, PCCs of all political colours have been a great success. They have cut crime and reset proper governance arrangements with the police.

PCCs suffered the accusations that they had no working mandate from the elections in November 2012: I can see the risk of a mirror-image situation arising in May.

Hundreds of millions of pounds of public money are at stake; partners are hanging on news of their new commissioning funding source; the criminal justice system awaits an end-to-end review in the hands of future PCCs, yet silence from the government.

It is simply not good enough to hear that the Government is in stasis over the EU referendum. There is a significant and costly democracy milestone awaiting public involvement two weeks away yet our public are drifting towards it as they have so little information on the role and candidates.

The role is not just about crime: the wider opportunities and risks are enormous.

On my third point, the following list my experiences of interaction with the party, both good and bad, during my role as police and crime commissioner.

On the positive side, I would be first to praise MPs for the sterling work they do in the community. Recently I was working with an MP in North Devon on a complex case of domestic abuse and we are joined up in supporting the victim.

I have a huge mailbag, including cases referred from MPs. My team and I have worked hard to provide solutions and explanations, or I have returned letters where it is in the MP’s capacity to resolve the issue.

With the chief constable I have met routinely with the MPs for Devon and Cornwall in London every six months and often I have met one-to-one to brief them on my work as PCC and hear their views. This seemed to work well in terms of collaboration.

On the more challenging side, PCCs have expressed views that local MPs have found it difficult to relate to the PCC as PCCs establish their executive powers in the community. I accept that the arrival of PCCs was a politically toxic subject but across the country we have already proved our worth with much still to do.

My relationship and synergy with MPs seemed healthy until the chips were down in the environment of extreme funding pressures in 2015 when the party and its ways seemed to come before people. Broad areas of difficulty for me before and after 2015 were:

There seems to be a fundamental lack of understanding by local MPs and probably the party as to the role of the PCC. The PCC is not simply another Party lever to be whipped into collective compliance; and voters don’t want this. Every PCC has enormous executive responsibilities in the community very different from the role of an MP. PCCs have also signed an oath of impartiality.

Some party officials saw the PCC role as a “stepping stone to the next general election”. It is quite wrong to use the role in this way.

With increasing public sector savings targets in 2015 I needed the support of my MPs but I was branded as “scaremongering” or “exaggerating” and assured that MPs had things in hand when in fact Home Office officials had confirmed my office’s accurate interpretation.

Slightly later, in the face of these threats, it was a constitutional option to consider a public referendum to provide a route for the public to pay more (should they wish to do so) to offset the devastating impact on policing. MPs’ response was that my stance in opening the options for a referendum (in order that the public had a choice to pay more to support policing) was contrary to party ideology. Who was putting the public first at that point?

In overthrowing the ineptly-handled police funding formula, I had little encouragement from the party or, £15million better off, any messages of praise for my team.

I could go on. To hear the Home Secretary (a woman I admire) suggest to voters that the only safe PCC was a Conservative one, was absurd, not least as she had just praised the Labour PCC for Northumbria for her work to reduce violence against women and girls and is supposed to provide support and leadership to all PCCs.

The PCC elections will provide a good opportunity for a restart in the relationships between PCC and our 18 MPs. If there is anything I have done that has been excessive or not in the public interest, I freely apologise. I feel sure that my successor (of whichever political colour) will form a close relationship with MPs to tackle the many challenges together. But the PCC, like our police which it is his or her privilege to govern, must remain impartial and distanced from party politics.”