Active in the Ulster Farmers' Union and in Unionist associations, he achieved senior office in the Orange Order and the Royal Black Institution and served on Omagh Rural District Council from 1952 until his death.
[6] He advertised the property he was auctioning weekly in local newspapers circulating in County Tyrone, including the Nationalist Ulster Herald.
[14] In June 1952, he attended a meeting of the County Tyrone Committee of the Ulster Farmers' Union at which he complained that a consignment of potatoes had been sent to Derry and left on the quay for six weeks before the Ministry had rejected them.
He gave in to the pressure and on 9 March was reappointed,[11] receiving with his letter of appointment a document identified as "A/cs.150" which stated "Service on the bodies referred to above is regarded as voluntary and unpaid".
[18] Representing Reaghan R.B.P., he was one of the platform party at a celebration of the Relief of Derry organised by Castlederg District Royal Black Chapter No.
He served as Deputy Lecturer of the Grand Royal Arch Purple of Ireland, and was District Master of Omagh Black Chapter.
[24] He was not a notably active councillor,[25] but on 4 March 1954 he handed in a petition from farmers in Cappagh, Dunbreen and neighbouring districts, calling for mains electricity supplies.
Mitchell was in HM Prison Belfast serving a sentence of ten years' imprisonment after he was caught during an Irish Republican Army raid on Omagh barracks.
[31] Although Mitchell as a Sinn Féin candidate did not have access to Nationalist halls to hold meetings, nor to those run by the Roman Catholic Church, he was still regarded as the favourite.
[33] A meeting to select the Unionist candidate was held on Saturday 14 May; among the other names considered were Charles A. Beattie (of Kingarrow), William J. Hamilton, Lt-Col. Alexander, Thomas Lyons (Stormont MP for North Tyrone), and J. P. Duff OBE.
[35] With Mitchell in prison serving ten years' imprisonment for treason felony, he was technically ineligible for election and the Unionists began to consider how they could get him disqualified.
He blamed apathy and carelessness in Unionist ranks for his defeat, and said that so-called loyalists who stayed at home playing a neutral part had indirectly supported Sinn Féin.
Beattie then insisted that he asked for support not for what he was, but for what he stood for, which he defined as civil and religious liberty for Roman Catholics and Protestants alike.
[47] When it came to trial, Tom Mitchell caused some surprise by deciding to attend the court;[48] however at the end of a three-day hearing, judgment was given for Beattie.
[51] On 25 October 1955, when the House of Commons assembled after the summer recess and received the report of the judges trying the election petition, Beattie took his seat.
[54] The following day, Leader of the House of Commons Harry Crookshank moved to refer Beattie to the Select Committee on Elections to investigate.
[58] The Attorney-General explained the operation of the law and contended that membership of the National Insurance Tribunals was disqualifying; however on investigating the County Agricultural Committees he advised that there was no issue.
[11] The Select Committee found that Beattie was indeed disqualified by his membership of the three appeal tribunals for which expenses could be paid, and ruled his election invalid.
[61] They recommended a Bill be brought in to indemnify him from the consequences of having acted as a Member of Parliament while disqualified (he was potentially liable for fines of £9,500)[53] but found it difficult to determine whether to validate his election and allow him to continue as an MP.
By the time he had been nominated as a candidate in the August by-election, three other MPs had been discovered to have held similar offices and a Select Committee had found them to be disqualified.
[69] His funeral on 12 March was said to be one of the largest ever witnessed in County Tyrone and the procession included 150 cars; Beattie is buried in Mountjoy Presbyterian Church in Omagh.